BIO 1305 Kang Final ch 1, 2, 3, 4, 5, 6, 7, 8,9,10, 11, 12, 13, 14, 15 16, 17

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Nitrogen (N) normally forms three covalent bonds with a valence of five. However, ammonium has four covalent bonds, each to a different hydrogen (H) atom (H has a valence of one). What do you predict to be the charge on ammonium? A) +1 B) -1 C) +2 D) -2

During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a ∆G of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the ∆G for the new reaction? A) -40 kcal/mol B) -20 kcal/mol C) -10 kcal/mol D) +20 kcal/mol

-20 kcal/mol

In pea plants, the tall phenotype is dominant to the dwarf phenotype. If a heterozygous pea plant is crossed with a homozygous tall pea plant, what is the probability that the offspring will be dwarf in size? A) 1 B) 1/2 C) 1/4 D) 0

The following question refers to the pedigree chart in the figure for a family, some of whose members exhibit the dominant trait, W. Affected individuals are indicated by a dark square or circle. What is the probability that individual III-1 is Ww? A) 3/4 B) 1/4 C) 2/4 D) 1

Which temperature and pH profile curves on the graphs are most likely associated with an enzyme isolated from a human stomach where conditions are strongly acid? A) curves 1 and 4 B) curves 1 and 5 C) curves 2 and 4 D) curves 3 and 4

1 and 4

Use the figure and the following description to answer the question. In a particular plant, leaf color is controlled by gene locus D. Plants with at least one allele D have dark green leaves, and plants with the homozygous recessive dd genotype have light green leaves. A true-breeding, dark-leaved plant is crossed with a light-leaved one, and the F1 offspring is allowed to self-pollinate. The predicted outcome of the F2 is diagrammed in the Punnett square shown in the figure, where 1, 2, 3, and 4 represent the genotypes corresponding to each box within the square. Which of the boxes marked 1-4 correspond to plants that will be true-breeding? A) 1 and 4 only B) 2 and 3 only C) 1, 2, 3, and 4 D) 1 only

1 and 4 only

When an ionic compound such as sodium chloride (NaCl) is placed in water, the component atoms of the NaCl crystal dissociate into individual sodium ions (Na+) and chloride ions (Cl-). In contrast, the atoms of covalently bonded molecules (e.g., glucose, sucrose, glycerol) do not generally dissociate when placed in aqueous solution. Which of the following solutions would be expected to contain the greatest number of solute particles (molecules or ions)? A) 1 liter of 0.5 M NaCl B) 1 liter of 1.0 M NaCl C) 1 liter of 1.0 M glucose D) 1 liter of 1.0 M NaCl and 1 liter of 1.0 M glucose will contain equal numbers of solute

1 liter of 1.0 M NaCl

Which one of the atoms shown would be most likely to form a cation with a charge of +1?

1 valence electron in shell

Assume that acid rain has lowered the pH of a particular lake to pH 5.0. What is the hydroxide ion concentration of this lake? A) 1 × 10-9 mol of hydroxide ions per liter of lake water B) 1 × 10-5 mol of hydroxide ions per liter of lake water C) 5.0 M hydroxide ion D) 5.0 × 10-5 mol of hydroxide ions per liter of lake water

1 x 10-9 mol hydroxide ions per liter

Use the following information to answer the question. A plantlike organism on the planet Pandora can have three recessive genetic traits: bluish leaves, due to an allele (a) of gene A; a feathered stem, due to an allele (b) of gene B; and hollow roots due to an allele (c) of gene C. The three genes are linked and recombine. A geneticist performed a testcross with an organism that had been found to be heterozygous for the three recessive traits, and she was able to identify progeny of the following phenotypic distribution (+ = wild type): Phenotypes Leaves Stems Roots Number 1 a + + 14 2 a + c 0 3 a b + 32 4 a b c 440 5 + b + 0 6 + b c 16 7 + + c 28 8 + + + 470 Total 1000 Which of the progeny phenotypes will require recombination between genes A and B? A) 1, 2, 5, and 6 B) 1, 3, 6, and 7 C) 2, 4, 5, and 8 D) 2, 3, 5, and 7

1, 2, 5, and 6

Use the figure and the following description to answer the question. In a particular plant, leaf color is controlled by gene locus D. Plants with at least one allele D have dark green leaves, and plants with the homozygous recessive dd genotype have light green leaves. A true-breeding, dark-leaved plant is crossed with a light-leaved one, and the F1 offspring is allowed to self-pollinate. The predicted outcome of the F2 is diagrammed in the Punnett square shown in the figure, where 1, 2, 3, and 4 represent the genotypes corresponding to each box within the square. Which of the boxes marked 1-4 correspond to plants with dark leaves? A) 1 only B) 2 and 3 C) 4 only D) 1, 2, and 3

1, 2, and 3

How much of 0.5 M glucose (molecular mass 180) is needed to provide 100 mg of glucose? A) 1.11 mL B) 0.11 mL C) 100 mL D) 10 mL

1.11 mL

When the system illustrated above reaches equilibrium, the SUGAR CONCENTRATIONS on both sides of the U-tube will be ________. A) 2 M sucrose, 1 M glucose B) 1 M sucrose, 2 M glucose C) 1 M sucrose, 1 M glucose D) 1.5 M sucrose, 1.5 M glucose

1.5 M sucrose 1.5 M glucose

A man has extra digits (six fingers on each hand and six toes on each foot). His wife and their daughter have the normal number of digits (five fingers on each hand and five toes on each foot.) Having extra digits is a dominant trait. The couple's second child has extra digits. What is the probability that their next (third) child will have extra digits? A) 1/2 B) 1/16 C) 1/8 D) 3/4

1/2

A recessive allele on the X chromosome is responsible for red-green color blindness in humans. A woman with normal vision whose father is color blind marries a color-blind male. What is the probability that this couple's first son will be color blind? A) 1/4 B) 1/2 C) 2/3 D) 3/4

1/2

Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long tails (t). What fraction of the progeny of crosses BbTt × BBtt will be expected to have black fur and long tails? A) 1/16 B) 3/8 C) 1/2 D) 9/16

1/2

Glucose-6-phosphate dehydrogenase deficiency (G6PD) is inherited as an X-linked recessive allele in humans. A woman whose father suffered from G6PD marries a man who has the disease. What proportion of their sons would have the disease? A) 100% B) 1/2 C) 1/4 D) zero

1/2

Glucose-6-phosphate dehydrogenase deficiency (G6PD) is inherited as an X-linked recessive allele in humans. A woman whose father suffered from G6PD marries a normal man. What proportion of their sons is expected to be G6PD? A) 100% B) 1/4 C) 1/2 D) zero

1/2

Skin color in a certain species of fish is inherited via a single gene with four different alleles. One fish of this type has alleles 1 and 3 (S1S3), and its mate has alleles 2 and 4 (S2S4). If each allele confers a unit of color darkness such that S1 has one unit, S2 has two units, and so on, then what proportion of their offspring would be expected to have five units of color? A) 1/4 B) 1/8 C) 1/2 D) 0

1/2

A certain kind of snail can have a right-handed direction of shell coiling (DD or Dd) or left-handed coiling (dd). However, if direction of coiling is due to a protein deposited by the mother in the egg cytoplasm, then a Dd egg-producing snail and a dd sperm-producing snail will have offspring of which genotype(s) and phenotype(s)? A) 1/2 Dd:1/2 dd; all right-coiling B) all Dd; all right-coiling C) 1/2 Dd: 1/2 dd; half right-coiling and half left-coiling D) all Dd; half right-coiling and half left-coiling

1/2 Dd:1/2 dd; all right-coiling

If glucose is the sole energy source, what fraction of the carbon dioxide exhaled by animals is generated only by the reactions involved in oxidation of pyruvate to acetyl CoA? A) 1/6 B) 1/3 C) 2/3 D) all of it

1/3

Albinism is a recessive trait. A man and woman both show normal pigmentation, but both have one parent who has albinism (without melanin pigmentation). What is the probability that their first child will have albinism? A) 0 B) 1/2 C) 1/4 D) 1

1/4

The pattern of inheritance can be predicted from data if one is given the parent or offspring genotypes or phenotypes. Two organisms, with genotypes BbDD and BBDd, are mated. Assuming independent assortment of the B/b and D/d genes, determine the genotypic ratios in offspring that would occur. A) 1/2 BBDD, 1/2 bbdd B) 1/4 BBDD, 1/4 BbDD, 1/4 BBDd, 1/4 BbDd C) 9/16 BBDD, 3/16 BbDD, 3/16 BBDd, 1/16 bbdd D) 1/4 BBDD, 1/2 BbDd, 1/4 bbdd

1/4 BBDD, 1/4 BbDD, 1/4 BBDd, 1/4 BbDd

Suppose two individuals with the genotype AaBbCc are mated. Assuming that the genes are not linked, what fraction of the offspring are expected to be homozygous recessive for the three traits? A) 1/4 B) 1/8 C) 1/16 D) 1/64

1/64

What is the probability of producing the genotype AABBCC in a cross of individuals who both possess this genotype: AaBbCc? A) 1/4 B) 1/8 C) 1/16 D) 1/64

1/64

Assuming independent assortment for all gene pairs, what is the probability that a cross between the following parents, AABbCc × AaBbCc, will produce an AaBbCc offspring? A) 1/2 B) 1/16 C) 1/8 D) 3/4

1/8

A slice of pizza has 500 kcal. If we could burn the pizza and use all the heat to warm a 50-L container of cold water, what would be the approximate increase in the temperature of the water? (Note: A liter of cold water weighs about 1 kg.) A) 50°C B) 5°C C) 100°C D) 10°C

If a cell at metaphase of mitosis contains 20 sister chromatids, how many CHROMOSOMES will be present in a G1 cell? A) 5 B) 10 C) 20 D) 40

In a diploid cell with 5 chromosome pairs (2n = 10), how many CENTROMERES will be found in a nucleus at G2 of the cell division cycle? A) 5 B) 10 C) 20 D) 40

Measurements show that the pH of a particular lake is 4.0. What is the hydroxide ion concentration of the lake? A) 10-10 M B) 10-4 M C) 10-7 M D) 10.0 M

10 -10

Measurements show that the pH of a particular lake is 4.0. What is the hydrogen ion concentration of the lake? A) 4.0 M B) 10-10 M C) 10-4 M D) 104 M

10-4

What is the hydroxyl ion (OH-) concentration of a solution of pH 8? A) 8 M B) 8 × 10-6 M C) 10-8 M D) 10-6 M

10-6

Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed by the reactions of glycolysis? A) 0% B) 2% C) 38% D) 100%

100

A solution with a pH of 2 has how many more protons in it than a solution with a pH of 4? A) 5 times more B) 10 times more C) 100 times more D) 1000 times more

100 times more times 2= (10)(10)

Cinnabar eye color is a sex-linked, recessive characteristic in fruit flies. If a female having cinnabar eyes is crossed with a wild-type male, what percentage of the F1 males will have cinnabar eyes? A) 0% B) 25% C) 50% D) 100%

100%

A dietary Calorie equals 1 kilocalorie. One kilocalorie equals ________. A) 1000 calories, or the amount of heat required to raise the temperature of 1 g of water by 1°C B) 10,000 calories, or the amount of heat required to raise the temperature of 1 kg of water by 1°F C) 1000 calories, or the amount of heat required to raise the temperature of 1 kg of water by 1°C D) 1000 calories, or the amount of heat required to raise the temperature of 100 g of water by 100°C

1000 calories, or the amount of heat required to raise the temperature of 1kg of water by 1 degree C

What is the atomic number of the cation formed in the reaction in the illustration? A) 8 B) 10 C) 11 D) 16

Which of the following combinations of molecules illustrated could be linked to form a nucleotide? A) 1, 2, and 11 B) 3, 7, and 8 C) 5, 9, and 10 D) 11, 12, and 13

11 12 13

How many electrons are present in a Phosphorus 3+ atom? A) 16 B) 12 C) 19 D) 34

How many heme groups are present in three hemoglobin protein molecules? A) 3 B) 4 C) 9 D) 12

If a cell is able to synthesize 30 ATP molecules for each molecule of glucose completely oxidized to carbon dioxide and water, approximately how many ATP molecules can the cell synthesize for each molecule of pyruvate oxidized to carbon dioxide and water? A) 8 B) 12.5 C) 16 D) 25

12.5

Use the following figure to answer the question. Two moles of the compound in the figure would weigh how many grams? (Note: The atomic masses, in daltons, are approximately 12 for carbon, 1 for hydrogen, and 16 for oxygen.) A) 30 B) 60 C) 90 D) 120

120

Which of the following molecules is a purine nitrogenous base? A) 2 B) 5 C) 12 D) 13

A homozygous tomato plant with red fruit and yellow flowers was crossed with a homozygous tomato plant with golden fruit and white flowers. The F1 all had red fruit and yellow flowers. The F1 were testcrossed by crossing them to homozygous recessive individuals, and the following offspring were obtained: Red fruit and yellow flowers—41 Red fruit and white flowers—7 Golden fruit and yellow flowers—8 Golden fruit and white flowers—44 How many map units separate these genes? A) 17.6 B) 15 C) 17.1 D) 18.1

A group of cells is ASSAYED for DNA content immediately following mitosis and is found to have an average of 8 PICOGRAMSs of DNA per nucleus. How many picograms of DNA would be found in a nucleus at PROPHASE of mitosis? A) 4 B) 8 C) 16 D) 24

Oxygen has an atomic number of 8 and, most commonly, a mass number of 16. Thus, what is the atomic mass of an oxygen atom? A) approximately 8 grams B) approximately 8 daltons C) approximately 16 grams D) approximately 16 daltons

16 DALTONS

The molar mass of glucose is 180 grams per mole (g/mol). Which of the following procedures should you carry out to make a 1 M solution of glucose? In 0.8 liter (L) of water, dissolve ________. A) 1 g of glucose, and then add more water until the total volume of the solution is 1 L B) 18 g of glucose, and then add more water until the total volume of the solution is 1 L C) 180 g of glucose, and then add 0.2 L more of water D) 180 g of glucose, and then add more water until the total volume of the solution is 1 L

180 g of glucose, then add more water until the total volume is 1 L

One mole (mol) of glucose (molecular mass = 180 daltons) is ________. A) 180 × 1023 molecules of glucose B) 1 kilogram of glucose dissolved in 1 liter of solution C) 180 mL of dissolved glucose D) 180 grams of glucose

180 grams of glucose

How many molecules of water are released during the POLYMERIZATION of a 20 monomer-long cellulose molecule? A) 10 B) 19 C) 20 D) 40

When Mendel crossed yellow-seeded and green-seeded pea plants, all the offspring were yellow-seeded. When he took these F1 yellow-seeded plants and crossed them to green-seeded plants, what genotypic ratio was expected? A) 1:2:1 B) 3:1 C) 1:1 D) 1:1:1:1

1:1

Which of the following will have the greatest ratio of surface area to volume? A) A box that is 2×2×2. B) A box that is 1×1×1. C) A box that is 2×2×1. D) A box that is 1×1×2.

1X1X1

Use the figure to answer the question. The figure shows a simple metabolic pathway. According to BEADLE AND TATUM' hypothesis, how many genes are necessary for this pathway? A) 1 B) 2 C) 3 D) It cannot be determined from the pathway.

What is the maximum number of covalent bonds that an oxygen atom with atomic number 8 can make with hydrogen? A) 1 B) 2 C) 4 D) 6

Which of the following molecules act as building blocks (monomers) of polypeptides? A) 1, 4, and 6 B) 2, 7, and 8 C) 7, 8, and 13 D) 11, 12, and 13

2 7 8

Starting with one molecule of glucose, glycolysis results in the net production of which of the following sets of energy-containing products? A) 2 NAD+, 2 pyruvate, and 2 ATP B) 2 NADH, 2 pyruvate, and 2 ATP C) 4 NADH, 2 pyruvate, and 4 ATP D) 6 CO2, 2 pyruvate, and 2 ATP

2 NADH, 2 pyruvate, and 2 ATP

Use the figure and the following description to answer the question. In a particular plant, leaf color is controlled by gene locus D. Plants with at least one allele D have dark green leaves, and plants with the homozygous recessive dd genotype have light green leaves. A true-breeding, dark-leaved plant is crossed with a light-leaved one, and the F1 offspring is allowed to self-pollinate. The predicted outcome of the F2 is diagrammed in the Punnett square shown in the figure, where 1, 2, 3, and 4 represent the genotypes corresponding to each box within the square. Which of the boxes marked 1-4 correspond to plants with a heterozygous genotype? A) 1 B) 1, 2, and 3 C) 2 and 3 D) 2, 3, and 4

2 and 3

If there are 40 centromeres in a cell at anaphase of mitosis, how many chromosomes will be found in EACH DAUGHTER cell following cytokinesis? A) 10 B) 20 C) 40 D) 80

In a diploid cell with 5 chromosome pairs (2n = 10), how many SISTER CHROMATIDS will be found in a nucleus at PROPHASE OF MITOSIS? A) 5 B) 10 C) 20 D) 40

Thymine makes up 28% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this sample will be guanine? A) 8% B) 16% C) 22% D) 72%

In rabbits, the homozygous genotype LCLC has normal legs, LCLc results in deformed legs, and LcLc results in very short legs. The genotype FBFB produces black fur, FBFb brown fur, and FbFb white fur. If a cross is made between brown rabbits with deformed legs and white rabbits with deformed legs, what percentage of the offspring would be expected to have deformed legs and white fur? A) 25% B) 33% C) 100% D) 50%

25%

In birds, sex is determined by a ZW chromosome scheme. Males are ZZ and females are ZW. A recessive lethal allele that causes death of the embryo is sometimes present on the Z chromosome in pigeons. What would be the sex ratio in the offspring of a cross between a male that is heterozygous for the lethal allele and a normal female? A) 2:1 male to female B) 1:2 male to female C) 1:1 male to female D) 3:1 male to female

2:1 male to female

What coefficients must be placed in the following blanks so that all atoms are accounted for in the products? C6H12O6 → ________ C2H6O + ________ CO2 A) 2; 1 B) 3; 1 C) 1; 3 D) 2; 2

2; 2

In carbohydrates, the ratio of hydrogen (H) to oxygen (O) is ________. A) 1:1 B) 2:1 C) 3:1 D) 4:1

2;1

If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I will be A) 0.25x. B) 0.5x. C) x. D) 2x.

2x.

In an ETHAN (C2H6) molecule, each carbon atom is bonded to ________ hydrogen atoms. A) two B) three C) four D) six

Starting with citrate, which of the following combinations of products would result from three acetyl CoA molecules entering the citric acid cycle? A) 1 ATP, 2 CO2, 3 NADH, and 1 FADH2 B) 3 ATP, 3 CO2, 3 NADH, and 3 FADH2 C) 3 ATP, 6 CO2, 9 NADH, and 3 FADH2 D) 6 ATP, 6 CO2, 3 NADH, and 12 FADH2

3 ATP, 6 CO2, 9 NADH, and 3 FADH2

Which curves on the graphs may represent the temperature and pH profiles of an enzyme taken from a bacterium that lives in a mildly alkaline hot springs at temperatures of 70°C or higher? A) curves 1 and 5 B) curves 2 and 5 C) curves 3 and 4 D) curves 3 and 5

3 and 5

Use the following information to answer the question. A plantlike organism on the planet Pandora can have three recessive genetic traits: bluish leaves, due to an allele (a) of gene A; a feathered stem, due to an allele (b) of gene B; and hollow roots due to an allele (c) of gene C. The three genes are linked and recombine. A geneticist performed a testcross with an organism that had been found to be heterozygous for the three recessive traits, and she was able to identify progeny of the following phenotypic distribution (+ = wild type): Phenotypes Leaves Stems Roots Number 1 a + + 14 2 a + c 0 3 a b + 32 4 a b c 440 5 + b + 0 6 + b c 16 7 + + c 28 8 + + + 470 Total 1000 If recombination frequency is equal to distance in map units, what is the approximate distance between genes A and B? A) 3 map units B) 6 map units C) 15 map units D) 30 map units

3 map units

A particular triplet of bases in the template strand of DNA is 5′-AGT-3′. What would be the CORRESPONDING CODON for the mRNA that is transcribed? A) 3′-UCA-5′ B) 3′-UGA-5′ C) 5′-TCA-3′ D) 3′-ACU-5′

3' - UCA - 5'

The following question refers to this table of codons. Which of the following sequences of nucleotides are possible in the template strand of DNA that would code for the polypeptide sequence PHE LEU ILE VAL A) 5′-TTG-CTA-CAG-TAG-3′ B) 5′-AUG-CTG-CAG-TAT-3′ C) 3′-AAA-AAT-ATA-ACA-5′ D) 3′-AAA-GAA-TAA-CAA-5′

3' AAA GAA TAA CAA 5'

Which of the following anticodons in the first tRNA to bind will complement this mRNA? A) 3′-GGC-5′ B) 5′-GGC-3′ C) 5′-UGC-3′ D) 3′-UGC-5′

3' GGC 5"

Refer to the figure. Which of the triplets below is a possible anticodon for a tRNA that TRANSPORTS PROLINE to a ribosome? A) 3′-UUC-5′ B) 3′-CCG-5′ C) 3′-GGC-5′ D) 3′-CCC-5′

3' GGC 5'

Put the steps of the process of signal transduction in the order they occur. 1. A conformational change in the signal-receptor complex activates an enzyme. 2. Protein kinases are activated. 3. A signal molecule binds to a receptor. 4. Target proteins are phosphorylated. 5. Second messenger molecules are released. A) 1, 2, 3, 4, 5 B) 3, 1, 2, 4, 5 C) 3, 1, 5, 2, 4 D) 1, 2, 5, 3, 4

3, 1, 5, 2, 4

Two true-breeding stocks of pea plants are crossed. One parent has red, axial flowers, and the other has white, terminal flowers; all F1 individuals have red, axial flowers. The genes for flower color and location assort independently. Among the F2 offspring, what is the probability of producing plants with white axial flowers? A) 9/16 B) 1/16 C) 3/16 D) 1/4

3/16

Given the following genotypes for two parents, AABBCc × AabbCc, assume that all traits exhibit simple dominance and independent assortment. What proportion of the progeny of this cross will be expected to phenotypically resemble the first parent with the genotype AABBCc? A) 1/4 B) 3/4 C) 3/8 D) 1

3/4

Phenylketonuria is an inherited disease caused by a recessive autosomal allele. If a woman and her husband are both carriers, what is the probability that their first child will be a phenotypically normal girl? A) 1/4 B) 1/16 C) 3/16 D) 3/8

3/8

How many grams of the compound in the figure are required to make 1 liter of a 0.5 M solution? (Note: The atomic masses, in daltons, are approximately 12 for carbon, 1 for hydrogen, and 16 for oxygen.) A) 30 B) 60 C) 90 D) 120

Approximately how many molecules of ATP are produced from the complete oxidation of one molecule of glucose (C6H12O6) in aerobic cellular respiration? A) 2 B) 4 C) 18-24 D) 30-32

30-32

Quaking aspen trees can send out underground stems for asexual reproduction. Sexual reproduction is not as common, but when it does happen, the haploid gametes have 19 chromosomes. How many chromosomes are in the cells of the underground stems? A) 9 B) 10 C) 19 D) 38

If one strand of a DNA molecule has the sequence of bases 5′-ATTGCA-3′, the mRNA synthesized following the template will be ________. A) 5′-TAACGT-3′ B) 5′-TGCAAT-3′ C) 3′-UAACGU-5′ D) 5′-UGCAAU-3′

3′-UAACGU-5′

For each mole of glucose (C6H12O6) oxidized by cellular respiration, how many moles of CO2 are released in the citric acid cycle (see the accompanying figure)? A) 2 B) 4 C) 6 D) 32

How many electrons does one atom of CARBON SHARE to complete its VALENCE shell? A) 2 B) 3 C) 4 D) 8

Skin color in a certain species of fish is inherited by a single gene with four different alleles. How many different types of gametes would be possible in this organism? A) 2 B) 4 C) 8 D) 16

Use the following information to answer the question. A plantlike organism on the planet Pandora can have three recessive genetic traits: bluish leaves, due to an allele (a) of gene A; a feathered stem, due to an allele (b) of gene B; and hollow roots due to an allele (c) of gene C. The three genes are linked and recombine. A geneticist performed a testcross with an organism that had been found to be heterozygous for the three recessive traits, and she was able to identify progeny of the following phenotypic distribution (+ = wild type): Phenotypes Leaves Stems Roots Number 1 a + + 14 2 a + c 0 3 a b + 32 4 a b c 440 5 + b + 0 6 + b c 16 7 + + c 28 8 + + + 470 Total 1000 Which of the following are the phenotypes of the parents in this cross? A) 2 and 5 B) 1 and 6 C) 4 and 8 D) 3 and 7

4 and 8

What WAVELENGTH of light in the figure is most effective in driving photosynthesis? A) 420 nm B) 575 nm C) 625 nm D) 730 nm

420

Rank the following ONE-BASE POINT MUTATIONs with respect to their LIKELIHOOD OF AFFECTING the structure of the corresponding polypeptide (from most likely to least likely). 1. insertion mutation deep within an intron 2. substitution mutation at the third position of a codon in an exon 3. substitution mutation at the second position of a codon in an exon 4. deletion mutation within the first exon of the gene A) 1, 2, 3, 4 B) 4, 3, 2, 1 C) 2, 1, 4, 3 D) 3, 1, 4, 2

4321

Of the following human aneuploidies, which is the one that generally has the most severe impact on the health of the individual? A) 47, trisomy 21 B) 47, XXY C) 47, XXX D) 45, X

47, trisomy 21

Which molecule has both hydrophilic and hydrophobic properties and is found in plasma membranes? A) 1 B) 5 C) 12 D) 14

The figure represents tRNA that RECOGNIZES AND BINDS a particular amino acid (in this instance, phenylalanine). Which codon on the mRNA strand codes for this amino acid? A) 5′-UGG-3′ B) 3′-GUG-5′ C) 5′-GUA-3′ D) 5′-UUC-3′

5 UUC 3

At a specific area of a chromosome, the sequence of nucleotides below is present where the chain opens to form a replication fork: 3' C C T A G G C (T) G C A A T C C 5' An RNA primer is formed starting at the underlined T (T) of the template. Which of the following represents the primer sequence? A) 5' G C C T A G G 3' B) 5' A C G T T A G G 3' C) 5' A C G U U A G G 3' D) 5' G C C U A G G 3'

5' ACGUUAGG 3'

Referring to the figure, what bases will be added to the primer as DNA replication proceeds? A) 5′ C, A, G, C, A, G, A 3′ B) 3′ T, C, T, G, C, T, G 5′ C) 5′ A, G, A, C, G, A, C 3′ D) 3′ G, T, C, G, T, C, T 5′

5' AGACGAC 3'

Use this model of a eukaryotic transcript to answer the following question. E = exon and I = intron 5′-UTR E1 I1 E2 I2 E3 I3 E4 UTR-3′ Which components of the previous molecule will also be found in mRNA in the cytosol? A) 5′-UTR I1 I2 I3 UTR-3′ B) 5′-E1 E2 E3 E4-3′ C) 5′-UTR E1 E2 E3 E4 UTR-3′ D) 5′-E1 I1 E2 I2 E3 I3 E4-3′

5' UTR E1 E2 E3 E4 UTR 3'

The following question refers to the pedigree chart in the figure for a family, some of whose members exhibit the dominant trait, W. Affected individuals are indicated by a dark square or circle. What is the likelihood that the offspring of IV-3 and IV-4 will have the trait? A) 0% B) 50% C) 75% D) 100%

50%

How many electrons are involved in a triple covalent bond? A) 3 B) 6 C) 9 D) 12

How many electrons will a single atom of sulfur with no charge and no bonds have in its valence shell? A) 6 B) 8 C) 16 D) 32

You have a freshly prepared 0.1 M sucrose (molecular mass 342) solution, which means ________. A) 6.02 × 1023 of sucrose molecules are present in the solution B) 6.02 × 1022 of sucrose molecules are present in the solution C) 34.2 g of sucrose is present in the solution D) 6.02 × 1022 of sucrose molecules or 34.2 g of sucrose is present in the solution

6.02x 10^22 of sucrose molecules or 34.2 grams of sucrose is present in the solution

A triploid cell contains three sets of homologous chromosomes. If a cell of a diploid species that normally has 42 chromosomes per cell is triploid, this cell would be expected to have which of the following sets of chromosomes? A) 63 chromosomes in 31 1/2 pairs B) 63 chromosomes in 21 sets of 3 C) 63 chromosomes, each with 3 sister chromatids D) 21 chromosome pairs and 21 unique chromosomes

63 chromosomes in 21 sets of 3

Starting with a fertilized egg (zygote), a series of SIX CELL DIVISIONS would produce an EARLY EMBRYO with how many cells? A) 12 B) 16 C) 32 D) 64

Which of the following pairs of molecules could be joined together by a peptide bond in a dehydration reaction? A) 2 and 3 B) 7 and 8 C) 8 and 9 D) 12 and 13

7 8

Which one of the atoms shown would be most likely to form an anion with a charge of -1?

7 valence electron in shell

Cytosine makes up 42% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this sample will be thymine? A) 8% B) 16% C) 42% D) 58%

How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEE? A) 4 B) 8 C) 16 D) 64

The atomic number of nitrogen is 7. Nitrogen-15 has a greater mass number than nitrogen-14 because the atomic nucleus of nitrogen-15 contains ________. A) 7 neutrons B) 8 neutrons C) 8 protons D) 15 protons

8 neutrons

We can represent atoms by listing the number of protons, neutrons, and electrons—for example, 2p+, 2n0, 2e- for helium. Which of the following represents the 18 O isotope of oxygen? A) 7p+, 2n0, 9e- B) 8p+, 10n0, 8e- C) 9p+, 9n0, 9e- D) 10p+, 8n0, 9e-

8P+, 10n0, 8e-

Which molecule is a saturated fatty acid? A) 1 B) 5 C) 8 D) 9

Gene S controls the sharpness of spines in a type of cactus. Cacti with the dominant allele, S, have sharp spines, whereas homozygous recessive ss cacti have dull spines. At the same time, a second gene, N, determines whether or not cacti have spines. Homozygous recessive nn cacti have no spines at all. If cacti heterozygous for both traits, SsNn, were allowed to self-pollinate, the offspring would segregate into which of the following phenotype ratios? A) 3 sharp-spined:1 spineless B) 1 sharp-spined:2 dull-spined:1 spineless C) 1 sharp-spined:1 dull-spined:1 spineless D) 9 sharp-spined:3 dull-spined:4 spineless

9 sharp-spined:3 dull-spined:4 spineless

Use the figures to answer the question. Which molecule has AT LEAST ONE CARBON atom attached to three different chemical groups? A) A B) B C) D D) A and B

Use the figures to answer the question. Which molecule shown has a carbonyl functional group in the form of an ALDEHYDE? A) A B) B C) C D) D

Use the figures to answer the question. Which molecules shown contain aCARBONYL GROUP? A) A and B B) B and C C) B, C, and D D) C and D

Use the figures to answer the question. Which of the functional groups shown is present in ETHANOL BUT NOT ETHAN? A) A B) B C) C D) D

Which component in the accompanying figure is a protein fiber of the EXTRACELLULAR MATRIX? A) A B) B C) C D) E

Which of the following statements supports the ONE-GENE ENZYME hypothesis? A) A mutation in a single gene can result in a defective protein. B) Alkaptonuria results when individuals lack multiple enzymes involved in the catalysis of homogentisic acid. C) Sickle-cell anemia results in normal hemoglobin. D) Multiple antibody genes can code for different related proteins, depending on the splicing that takes place post-transcriptionally.

A MUTATION in a single gene can result in a DEFECTIVE PROTEIN

The most COMMONLY OCCURRING MUTATION in people with CYSTIC FIBROSIS is a deletion of a single codon. What is the result of this type of mutation? A) a base-pair substitution B) a frameshift mutation C) a polypeptide missing an amino acid D) a nonsense mutation

A POLYPEPTIDE missing an amino acid

In humans, ABO blood types refer to glycoproteins in the membranes of red blood cells. There are three alleles for this autosomal gene: IA, IB, and i. The IA allele codes for the A glycoprotein, The IB allele codes for the B glycoprotein, and the i allele doesn't code for any membrane glycoprotein. IA and IB are codominant, and i is recessive to both IA and IB. People with type A blood have the genotypes IAIA or IAi, people with type B blood are IBIB or IBi, people with type AB blood are IAIB, and people with type O blood are ii. If a woman with type AB blood marries a man with type O blood, which of the following blood types could their children possibly have? A) A and B B) AB and O C) A, B, and O D) A, B, AB, and O

A and B

Use the following map of four genes on a chromosome to answer the question. Between which two genes would you expect the highest frequency of recombination? A) A and W B) E and G C) A and E D) A and G

A and G

Which of the following statements correctly describes what happens to a chromosome after a nonreciprocal translocation occurs? A) A deletion of part of the chromosome occurs. B) A duplication of part of the chromosome occurs. C) Nondisjunction of pairs of homologous occurs. D) A chromosome transfers a fragment but receives none in return.

A chromosome transfers a fragment but receives none in return.

Which of the following statements is consistent with the second law of thermodynamics? A) A gain of free energy in a system is always associated with conversion of energy from one form to another. B) A constant input of energy is required to maintain the high level of cellular organization. C) Without an input of energy, the entropy of an organism would tend to decrease over time. D) Every energy transformation performed by an organism decreases the entropy of the universe.

A constant input of energy is required to maintain the high level of cellular organization.

Which of the following statements is correct in describing the terms monohybrid cross and dihybrid cross? A) A monohybrid cross involves a single parent, whereas a dihybrid cross involves two parents. B) A dihybrid cross involves organisms that are heterozygous for two characters that are being studied, and a monohybrid cross involves organisms that are heterozygous for only one character being studied. C) A monohybrid cross is performed for one generation, whereas a dihybrid cross is performed for two generations. D) A monohybrid cross results in a 9:3:3:1 ratio, whereas a dihybrid cross gives a 3:1 ratio.

A dihybrid cross involves organisms that are heterozygous for two characters that are being studied, and a monohybrid cross involves organisms that are heterozygous for only one character being studied.

Which of the following statements describes an example of alternation of generations? A) A grandparent and grandchild each have dark hair, but the parent has blond hair. B) A diploid plant (sporophyte) produces a spore by meiosis that gives rise to a multicellular, haploid pollen grain (gametophyte). C) A diploid animal produces gametes by meiosis, and the gametes undergo fertilization to produce a diploid zygote. D) A haploid mushroom produces gametes by mitosis, and the gametes undergo fertilization, which is immediately followed by meiosis.

A diploid plant (sporophyte) produces a spore by meiosis that gives rise to a multicellular, haploid pollen grain (gametophyte).

Generally, only female cats have the tortoiseshell phenotype for fur color. Which of the following statements explains this phenomenon? A) A male inherits only one allele of the X-linked gene controlling hair color. B) The Y chromosome has a gene blocking orange coloration. C) Only males can have Barr bodies. D) Multiple crossovers on the Y chromosome prevent orange pigment production.

A male inherits only one allele of the X-linked gene controlling hair color.

During the elongation phase of translation, which site in the ribosome represents theLOCATION WHERE THE CODON IS BEING READ? A) E site B) P site C) A site D) the large ribosomal subunit

A site

Which of the following statements is most likely true of a protein that cotransports glucose and sodium ions into the intestinal cells of an animal? A) Sodium and glucose compete for the same binding site in the cotransporter. B) Glucose entering the cell down its concentration gradient provides energy for uptake of sodium ions against the electrochemical gradient. C) Sodium ions can move down their electrochemical gradient through the cotransporter whether or not glucose is present outside the cell. D) A substance that blocks sodium ions from binding to the cotransport protein will also block the transport of glucose.

A substance that blocks sodium ions from binding to the cotransport protein will also block the transport of glucose.

In an analysis of the nucleotide composition of a molecule of DNA, which of the following combinations of base pairs will be found? A) A = C B) A = G and C = T C) A + C = G + T D) G + C = T + A

A+C = G+T

A particular triplet of bases in the coding sequence of DNA is AAA. The ANTICODN on the tRNA that binds the mRNA codon is ________. A) TTT B) UUA C) UUU D) AAA

AAA

The OXYGEN CONSUMED during cellular RESPIRATION is directly involved in which of the following processes or events? A) glycolysis B) accepting electrons at the end of the electron transport chain C) the citric acid cycle D) the oxidation of pyruvate to acetyl CoA

ACCEPTING ELECTRONS at end of ETC

Some CARBON SKELETONS have different numbers and locations of DOUBLE BONDS to ________. A) add molecular complexity and diversity that characterize living matter B) be more flexible that makes the molecule stronger C) stay in its liquid state D) increase its solubility in water

ADD molecular COMPLEXITY and DIVERSITY that characterize living matter

If photosynthesizing GREEN ALGAE are provided with CO2 containing heavy oxygen (18O), which of the following molecules produced by the algae (refer to the accompanying figure) will fail to contain 18O in later biochemical analyses? A) glyceraldehyde 3-phosphate (G3P) B) 3-phosphoglycerate C) ribulose bisphosphate (RuBP) D) ADP

ADP

In the formation of BIOFILMS, such as those forming on UNBRUSHED TEETH, cell signaling serves which function? A) formation of mating complexes B) aggregation of bacteria that can cause cavities C) secretion of substances that inhibit foreign bacteria D) digestion of unwanted parasite populations

AGGREGATION of BACTERIA that can cause CAVITIES

METAPHASE is characterized by ________. A) alignment of chromosomes on the equator of the cell B) separation of the centromeres C) cytokinesis D) separation of sister chromatids

ALIGNMENT of chromosomes on the equator of the cell

Which chemical group is most likely to be responsible for an ORGANIC MOLECULE BEHAVING AS A BASE? A) hydroxyl B) carbonyl C) amino D) phosphate

AMINO

The tRNA shown in the figure has its 3′ end PROJECTING beyond its 5′ end. Which of the following processes will occur at this 3′ end? A) The amino acid binds covalently. B) The excess nucleotides (ACCA) will be cleaved off at the ribosome. C) The small and large subunits of the ribosome will attach to it. D) The 5′ cap of the mRNA will become covalently bound.

AMINO ACID binds covalently

For a science fair project, two students decided to repeat the Hershey and Chase experiment, with modifications. They decided to radioactively label the nitrogen of the DNA, rather than the phosphate. They reasoned that each nucleotide has only one phosphate and two to five nitrogen atoms. Thus, labeling the nitrogen atoms would provide a stronger signal than labeling the phosphates. Why won't this experiment work? A) There is no radioactive isotope of nitrogen. B) Radioactive nitrogen has a half-life of 100,000 years, and the material would be too dangerous for too long. C) Although there are more nitrogens in a nucleotide, labeled phosphates actually have 16 extra neutrons; therefore, they are more radioactive. D) Amino acids (and thus proteins) also have nitrogen atoms; thus, the radioactivity would not distinguish between DNA and proteins.

AMINO ACIDS and thus proteins also have nitrogen atoms, thus, the radioactivity would not distinguish between DNA proteins

For a protein to be an INTEGRAL MEMBRANE PROTEIN, it would have to be ________. A) hydrophilic B) hydrophobic C) amphipathic, with at least one hydrophobic region D) exposed on only one surface of the membrane

AMPHIPATHIC at least one hydrophobic region

Which of the following molecules dramatically INCREASES THE RATE OF DIFFUSION of WATER across cell membranes? A) the sodium-potassium pump B) aquaporins C) gated ion channels D) ATP

AQUAPORINS

The figure shows the structures of GLUCOSE AND FRUCTOSE. These two molecules differ in the ________. A) number of carbon, hydrogen, and oxygen atoms B) types of carbon, hydrogen, and oxygen atoms C) arrangement of carbon, hydrogen, and oxygen atoms D) number of oxygen atoms joined to carbon atoms by double covalent

ARRANGEMENT of carbon, hydrogen, and oxygen atoms

What are the products of CYCLIC ELECTRON FLOW during the light reactions of photosynthesis? A) heat and fluorescence B) ATP C) ATP and NADPH D) ADP and NADP+

ATP

The light reactions of photosynthesis supply the Calvin cycle with A) light energy. B) CO2 and ATP. C) H2O and NADPH. D) ATP and NADPH.

ATP NADPH

Which of the following molecules are PRODUCTS OF THE LIGHT REACTIONS of photosynthesis that are utilized in the Calvin cycle? A) CO2 and glucose B) H2O and O2 C) ADP, i, and NADP+ D) ATP and NADPH

ATP NADPH

What are the products of LINEAR ELECTRON FLOW during the light reactions of photosynthesis? A) heat and fluorescence B) ATP and P700 C) ATP and NADPH D) ADP and NADP+

ATP and NADPH

The enzyme phosphofructokinase (PFK) catalyzes a key step in glycolysis. PFK is inhibited by high levels of which of the following molecules? A) glucose and NAD+ B) AMP and ATP C) ATP and citrate D) citrate and CO2

ATP and citrate

MOTOR PROTEINS require which of the following structures or molecules to function in the movement of chromosomes TOWARD THE POLES of the mitotic spindle? A) intact centromeres B) a microtubule-organizing center C) ATP as an energy source D) intact cohesin

ATP as energy source

Which of the following statements is true? A) ADP contains more energy than ATP. B) Following hydrolysis, ATP can give off one phosphate, whereas ADP cannot. C) ADP can have two positive charges. D) ATP can have four negative charges.

ATP can have FOUR NEGATIVE charges

Which of the following is the most correct interpretation of the figure? A) Energy from catabolism can be used directly for performing cellular work. B) ADP + i are a set of molecules that store energy for catabolism. C) ATP is a molecule that acts as an intermediary to store energy for cellular work. D) i acts as a shuttle molecule to move energy from ATP to ADP.

ATP is a molecule that acts as an intermediary to store energy for cellular work.

Which of the following statements describes a central role that ATP plays in cellular metabolism? A) Hydrolysis of ATP provides an input of free energy for exergonic reactions. B) ATP provides energy coupling between exergonic and endergonic reactions. C) Hydrolysis of the terminal phosphate group stores free energy that is used for cellular work. D) Its terminal phosphate bond is stronger than most covalent bonds in other biological macromolecules.

ATP provides energy coupling between exergonic and endergonic reactions.

In the absence of oxygen, yeast cells can obtain energy by fermentation, which results in the production of which of the following sets of molecules? A) ATP, CO2, and ethanol (ethyl alcohol) B) ATP, CO2, and lactate C) ATP, NADH, and ethanol D) ATP, CO2, and acetyl CoA

ATP, CO2, and ethanol (ethyl alcohol)

A number of systems for pumping ions across membranes are powered by ATP. Such ATP- powered pumps are often called ATPases, although they do not often hydrolyze ATP unless they are simultaneously transporting ions. Because small increases in calcium ions in the cytosol can trigger a number of different intracellular reactions, cells keep the cytosolic calcium concentration quite low under normal conditions, using ATP-powered calcium pumps. For example, muscle cells transport calcium from the cytosol into the membranous system called the sarcoplasmic reticulum (SR). If a resting muscle cell's cytosol has a free calcium ion concentration of 10-7 while the concentration in the SR is 10-2, then how is the ATPase acting? A) ATPase activity must be powering an inflow of calcium from the outside of the cell into the SR. B) ATPase activity must be transferring i to the SR to enable this to occur. C) ATPase activity must be pumping calcium from the cytosol to the SR against the concentration gradient. D) ATPase activity must be opening a channel for the calcium ions to diffuse back into the SR along the concentration gradient.

ATPase activity must be pumping calcium from the cytosol to the SR against the concentration gradient.

In the cells of many eukaryotic species, the NUCLEAR ENVELOPE has to DISAPPEAR to permit which of the following events in the cell cycle? A) DNA synthesis B) attachment of microtubules to kinetochores C) separation of the centrosomes D) condensation of the chromosomes

ATTACHMENT of MICROTUBULES

Which one of the following structures, IF MISSING, would usually PREVENT TRANSLATION from starting? A) exon B) 5′ cap C) AUG codon D) poly-A tail

AUG codon

Which of the following statements is a correct distinction between autotrophs and heterotrophs? A) Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic. B) Only heterotrophs require chemical compounds from the environment. C) Cellular respiration is unique to heterotrophs. D) Only heterotrophs have mitochondria.

AUTOTROPHS

Which of the following is true during a typical cAMP-mediated signal transduction event? A) The second messenger is the last part of the system to be activated. B) A hormone activates the second messenger by directly binding to it. C) The second messenger amplifies the hormonal response by attracting more hormones to the cell being affected. D) Adenylyl cyclase is activated after the hormone binds to the cell and before phosphorylation of proteins occurs.

Adenylyl cyclase is activated after the hormone binds to the cell and before phosphorylation of proteins occurs.

A black guinea pig crossed with a guinea pig with albinism produced 12 black offspring. When the albino was crossed with a second black animal, six blacks and six albinos were obtained. What is the best explanation for this genetic situation? A) Albinism is a recessive trait; black is a dominant trait. B) Albinism is a dominant trait; black is incompletely dominant. C) Albinism and black are codominant. D) Albinism is a recessive trait; black is codominant.

Albinism is a recessive trait; black is a dominant trait.

Which of the following statements correctly explains the fact that all seven of the pea plant traits studied by Mendel obeyed the principle of independent assortment? A) None of the traits obeyed the law of segregation. B) The diploid number of chromosomes in the pea plants was seven. C) All of the genes controlling the traits were located on the same chromosome. D) All of the genes controlling the traits behaved as if they were on different chromosomes.

All of the genes controlling the traits behaved as if they were on different chromosomes.

Misfolding of polypeptides is a serious problem in cells. Which of the following diseases are associated with an accumulation of misfolded polypeptides? A) Alzheimer's B) Parkinson's C) diabetes mellitus D) Alzheimer's and Parkinson's

Alzheimer's and Parkinson's

Density-dependent inhibition is explained by which of the following processes? A) As cells become more numerous, they begin to squeeze against each other, restricting their size. B) As cells become more numerous, the cell surface proteins of one cell contact the adjoining cells, and they signal each other to stop dividing. C) As cells become more numerous, the protein kinases they produce begin to compete with each other, such that the proteins produced by one cell essentially cancel those produced by its neighbor. D) As cells become more numerous, the level of waste products increases, which slows metabolism and inhibits growth.

As cells become more numerous, the cell surface proteins of one cell contact the adjoining cells, and they signal each other to stop dividing.

Which of the following is the best description of an atom's physical structure? A) An atom is a solid mass of material. B) The particles that form an atom are equidistant from each other. C) Atoms are little bubbles of space with mass concentrated at the center of the bubble. D) Atoms are little bubbles of space with mass concentrated on the outside surface of the bubble.

Atoms are little bubbles of space with mass concentrated at the CENTER of a bubble

A space probe returns with a culture of a microorganism found on a distant planet. Analysis shows that it is a carbon-based life-form that has DNA. You grow the cells in 15N medium for several generations and then transfer them to 14N medium. Which pattern in the figure would you expect if the DNA was replicated in a CONSERVATIVE manner?

Use the figures to answer the question. Which molecule can be a result of MERCAPTOETHANOL reduction of a disulfide bridge? A) A B) B C) C D) D

Use the figures to answer the question. Which molecule shown is a THIOL? A) A B) B C) C D) D

Use the figures to answer the question. Which of the groups is an acidic functional group that can DISSOCIATE AND RELEASE H+ into a solution? A) A B) B C) C D) D

What is the correct chromosomal condition at PROMETAPHASE of mitosis? A) B B) C C) D D) E

Which component in the accompanying figure plays a CRITICAL ROLE in CELL-CELL RECOGNITION? A) A B) B C) C D) E

Which line or lines in the graph represent(s) bags that contain a solution that is hypertonic at 50 minutes? A) A and B B) B C) D D) D and E

Refer to the accompanying figure and the molecules labeled A, B, C, D, and E. If the carbon atom of each of the incoming CO2 molecules is labeled with a RADIOACTIVE ISOTOPE of carbon, which organic molecules will be radioactively labeled after one cycle? A) C only B) B, C, D, and E C) C, D, and E only D) B and C only

B C D E

In human blood types, Rh positive is a trait that shows simple dominance over Rh negative. A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative. Which of the following phenotypes is possible for the father? A) A negative B) O negative C) B positive D) AB negative

B positive

Which domains of life are classified as prokaryotes? A) Bacteria and Eukarya B) Bacteria and Archaea C) Archaea and Fungi D) Bacteria and Protista

BACTERIA AND ARCAHAE

In YEAST SIGNAL TRANSDUCTION, a yeast cell releases a mating factor, which ________. A) acts back on the same cell that secreted the mating factor, changing its development B) passes through the membranes of neighboring cells, binds to DNA, and initiates transcription C) binds to receptors on the membranes of other types of yeast cells D) diffuses through the membranes of distant cells, causing them to produce factors that initiate long-distance migrations

BINDS to receptors

A GARDENER is concerned that her greenhouse is getting too hot from too much light and seeks to shade her plants with colored translucent plastic sheets, the color of which allows passage of only that wavelength. What color should she use to reduce overall light energy but still maximize plant growth? A) green B) blue C) orange D) Any color will work equally well.

BLUE

A SPACESHIP is designed to support animal life for a multiyear voyage to the outer planets of the solar system. Plants will be grown to provide oxygen and to recycle carbon dioxide. Since the spaceship will be too far from the sun for photosynthesis, an artificial light source will be needed. Suppose a plant has a unique photosynthetic pigment and the leaves of this plant appear to be reddish yellow. What wavelengths of visible light are absorbed by this pigment? A) red and yellow B) blue and violet C) green and yellow D) green and red

BLUE and VIOLET

Why might the alternative pathways of photosynthesis using C4 or CAM systems be described as metabolic compromises? A) Both pathways increase the rate of photosynthesis but also increase the rate of water loss. B) The CAM pathway allows more CO2 into the plant but also increases the rate of water loss. C) The C4 pathway decreases water loss but also increases the rate of photorespiration. D) Both pathways minimize photorespiration but also expend more ATP during carbon fixation.

BOTH MINIMIZE

STARCH is composed of ________. A) branched amylopectin and branched amylose B) unbranched amylopectin and unbranched amylose C) branched amylopectin and unbranched amylose D) unbranched amylopectin and branched amylose

BRANCHED AMYLOPECTIN and UNBRANCHED AMYLOSE

Which of the following statements describes a key component of the induced fit hypothesis of enzyme catalysis? A) Substrate binds to an allosteric site rather than to the active site of an enzyme. B) Binding of an activator molecule changes the shape of the active site of an enzyme. C) The conformation of the active site is determined by the tertiary or quaternary structure of the enzyme. D) Binding of substrate to the active site changes the shape of the active site of an enzyme.

Binding of substrate to the active site changes the shape of the active site of an enzyme.

Which of the following order is correct in terms of the hierarchy of the organization? A) Ecosystem → Biosphere → Population → Community → Organism B) Biosphere → Ecosystem → Population → Community → Organism C) Ecosystem → Community → Biosphere → Population → Organism D) Biosphere → Ecosystem →Community → Population → Organism

Biosphere → Ecosystem →Community → Population → Organism

Albinism is a recessive trait. A man and woman who both have normal pigmentation have one child out of three who has albinism (without melanin pigmentation). What are the genotypes of this child's parents? A) One parent must be homozygous for the recessive allele; the other parent can be homozygous dominant, homozygous recessive, or heterozygous. B) One parent must be heterozygous; the other parent can be homozygous dominant, homozygous recessive, or heterozygous. C) Both parents must be heterozygous. D) One parent must be homozygous dominant; the other parent must be heterozygous.

Both parents must be heterozygous.

Which of the following molecules is POLAR? C3H7OH C2H5COOH A) C3H7OH and C2H5COOH are both polar molecules. B) Neither C2H5COOH or C3H7OH is polar. C) C2H5COOH is polar, but C3H7OH is not polar. D) C2H5COOH is not polar, but C3H7OH is polar.

Both polar

Use the figures to answer the question. Which molecule shown can INCREASE CONCENTRATION of hydrogen ions in a solution and is therefore an organic acid? A) A B) B C) C D) D

Use the figures to answer the question. Which molecule shown contains a CARBOXYL group? A) A B) B C) C D) D

Which component in the accompanying figure is a MICROFILAMENT (aCtin filament) of the cytoskeleton? A) A B) B C) C D) D

Use the figures to answer the question. Which molecule(s) shown is (are) IONIZED in a cell? A) A B) B and D C) C and D D) D

C and D

Why has C. elegans proven to be a useful model for understanding apoptosis? A) C. elegans does not naturally use apoptosis, but can be induced to do so in the laboratory. B) C. elegans undergoes a fixed and easy-to-visualize number of apoptotic events during its normal development. C) C. elegans has large cells wherein apoptosis is easily observed without the aid of a microscope. D) As C. elegans ages, its cells die progressively until the whole organism is dead.

C. elegans undergoes a fixed and easy-to-visualize number of apoptotic events during its normal development

The molecular formula for glucose is C6H12O6. What would be the MOLECULAR FORMULA for a molecule made by linking three glucose molecules together by DEHYDRATION reactions? A) C18H36O18 B) C18H32O16 C) C6H10O5 D) C18H30O15

C18H32O16

Visualize the structural formula of each of the following hydrocarbons. Which hydrocarbon has a DOUBLE BOND IN ITS CARBON SKELETON? A) C3H8 B) C2H6 C) C2H4 D) C2H2

C2H4

Which of the following carbon molecules does not have the BOND ANGLE of 109.5°? A) CH4 B) C2H4 C) C2H6 D) C3H8

C2H4

What would be the expected effect on plants if the atmospheric CO2 concentration was doubled? A) All plants would have faster growth rates. B) C3 plants would have faster growth rates; C4 plants would be minimally affected. C) C4 plants would have faster growth rates; C3 plants would be minimally affected. D) C3 plants would have faster growth rates; C4 plants would have slower growth rates.

C3 faster, C4 MINIMALLY AFFECTED

Which of the following statements is true concerning the accompanying figure? A) It represents a C4 photosynthetic system. B) It represents an adaptation that maximizes photorespiration. C) It represents a C3 photosynthetic system. D) It represents a CAM photosynthetic system.

Which of the following metabolic processes can occur without a net influx of energy from some other process? A) ADP + → ATP + H2O B) C6H12O6 + 6O2 → 6CO2 + 6H2O C) 6CO2 + 6H20 → C6H12O6 + 6O2 D) Amino acids → Protein

C6H12O6 + 6O2 → 6CO2 + 6H2O

Which of the summary statements below describes the results of the following reaction? C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy A) C6H12O6 is oxidized and O2 is reduced. B) O2 is oxidized and H2O is reduced. C) CO2 is reduced and O2 is oxidized. D) O2 is reduced and CO2 is oxidized.

C6H12O6 OXIDIZED O2 REDUCED

Compared to C3 plants, C4 plants ________. A) can continue to fix CO2 even at lower CO2 concentrations and higher oxygen concentrations B) have higher rates of photorespiration C) do not use rubisco for carbon fixation D) make a four-carbon compound, oxaloacetate, which is then delivered to the citric acid cycle in mitochondria

CAN CONTINUE TO FIX

Use the figure to answer the question. What is the name of the functional group shown in the figure? A) carbonyl B) ketone C) aldehyde D) carboxyl

CARBOXYL

Which two functional groups are ALWAYS FOUND IN AMINO ACIDS? A) carbonyl and amino groups B) carboxyl and amino groups C) amino and sulfhydryl groups D) hydroxyl and carboxyl groups

CARBOXYL and AMINO ACIDS

A cell has enough available ATP to meet its needs for about 30 seconds. What is likely to happen when an ATHLETE EXHAUSTS his or her ATP supply? A) He or she has to sit down and rest. B) Catabolic processes are activated that generate more ATP. C) ATP is transported into the cell from the circulatory system. D) Other cells take over, and the muscle cells that have used up their ATP cease to function.

CATABOLIC PROCESSES activated that generate more ATP

Which of the following terms most precisely describes the cellular process of BREAKING DOWN large molecules into smaller ones? A) catabolism (catabolic pathways) B) metabolism C) anabolism (anabolic pathways) D) dehydration

CATABOLISM (catabolic pathways)

Referring to the accompanying figure, where would elevated concentrations of oxygen inhibit carbon fixation reactions? A) cell I only B) cell II only C) neither cell I nor cell II D) both cell I and cell II

CELL II ONLY

An ANIMAL CELL LACKING CARBOHYDRATES on the external surface of its plasma membrane would likely be impaired in which function? A) transporting ions against an electrochemical gradient B) cell-cell recognition C) attaching the plasma membrane to the cytoskeleton D) establishing a diffusion barrier to charged molecules

CELL-CELL RECOGNITION

What does the term insoluble fiber refer to on food packages? A) cellulose B) polypeptides C) starch D) amylopectin

CELLULOSE

You would like to LOSE WEIGHT. Which of the following should be your preferred FOOD GROUP? A) Lactose and glucose B) Sucrose and starch C) Starch and fructose D) Cellulose and fructose

CELLULOSE and FRUCTOSE

What is the name of the MICROTUBULE ORGANIZING CENTER found in animal cells as an identifiable structure present during all phases of the cell cycle? A) centriole B) centrosome C) centromere D) kinetochore

CENTROSOME

In what way do the MEMBRANES of a eukaryotic cell VARY? A) Phospholipids are found only in certain membranes. B) Certain proteins are unique to each membrane. C) Only certain membranes of the cell are selectively permeable. D) Some membranes have hydrophobic surfaces exposed to the cytoplasm while others have hydrophilic surfaces facing the cytoplasm.

CERTAIN PROTEINS are unique to each membrane

Which POLYSACCHARIDE is an important component in the structure of many ANIMALS and FUNGI? A) chitin B) cellulose C) amylopectin D) amylose

CHITIN

The drug CYTOCHALASIN B blocks the function of actin. Which of the following aspects of the animal cell cycle would be most disrupted by cytochalasin B? A) spindle formation B) spindle attachment to kinetochores C) movement of chromosomes to the poles during anaphase D) cleavage furrow formation and cytokinesis

CLEAVAGE FURROW

The drug cytochalasin B blocks the function of actin. Which of the following aspects of the animal cell cycle would be most disrupted by cytochalasin B? A) spindle formation B) spindle attachment to kinetochores C) cell elongation during anaphase D) cleavage furrow formation and cytokinesis

CLEAVAGE FURROW

FtsZ is a bacterial cytoskeletal protein that forms a CONTRACTILE RING involved in BINARY FISSION. Its function is analogous to ________. A) the cleavage furrow of eukaryotic animal cells B) the cell plate of eukaryotic plant cells C) the mitotic spindle of eukaryotic cells D) the microtubule-organizing center of eukaryotic cells

CLEAVAGE FURROW of eukaryotic animal cells

Codons are three-base sequences in mRNA that specify the addition of a single amino acid to the growing protein chain during translation. How do EUKARYOTIC CODONS AND PROKARYOTIC CODONS compare? A) Prokaryotic codons usually contain different bases than those of eukaryotes. B) Prokaryotic codons usually specify different amino acids than those of eukaryotes. C) The translation of codons is mediated by tRNAs in eukaryotes, but translation requires no intermediate molecules such as tRNAs in prokaryotes. D) Codons are a nearly universal language among all organisms.

CODONS are nearly UNIVERSAL

Which of the following statements about ANABOLIC pathways is true? A) They are usually spontaneous chemical reactions. B) They consume energy to build up polymers from monomers. C) They release energy by degrading polymers to monomers. D) They decrease the entropy of the organism and its environment.

CONSUME ENERGY to BUILD UP POLYMERS from monomers

Using Figure 17.6, identify a 5′ → 3′ sequence of nucleotides in the DNA template strand for an mRNA coding for the polypeptide sequence Phe-Pro-Lys. A) 5-UUUCCCAAA-3 B) 5-GAACCCCTT-3 C) 5-CTTCGGGAA-3 D) 5-AAACCCUUU-3

CTT

As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in one hour. You find that 30,000 molecules of ATP were consumed, but only 20,000 molecules of NADPH were consumed. What is the SOURCE OF THE EXTRA ATP molecules? A) photosystem II B) photosystem I C) cyclic electron flow D) linear electron flow

CYCLIC

Which of the following molecules is a protein synthesized at specific times during the cell cycle that associates with a kinase to form a catalytically active complex? A) PDGF B) MPF C) cyclin D) Cdk

CYCLIN

Once a cell enters mitosis, the molecules that activate division must be turned off. What happens to MPF during mitosis? A) It is completely degraded. B) It is phosphorylated by a Cdk, which inactivates it. C) The cyclin component of MPF is degraded. D) The Cdk component of MPF is degraded.

CYCLIN component of MPF is degraded

Through a MICROSCOPE, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely ________. A) an animal cell in the process of cytokinesis B) an animal cell in anaphase of mitosis C) a plant cell in the process of cytokinesis D) a plant cell in metaphase of mitosis

CYTOKINESIS

Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures? A) membrane proteins of the inner nuclear envelope B) free ribosomes and ribosomes attached to the ER C) components of the cytoskeleton D) cellulose fibers in the cell wall

CYTOSKELETON

Which of the following calculations require the use of the addition rule of probability? A) Calculate the probability of black offspring from the cross AaBb × AaBb, where B is the symbol for black. B) Calculate the probability of children with both cystic fibrosis and polydactyly when parents are each heterozygous for both genes. C) Calculate the probability of each of four children having cystic fibrosis if the parents are both heterozygous. D) Calculate the probability of a child having either sickle-cell anemia or cystic fibrosis if parents are each heterozygous for both.

Calculate the probability of a child having either sickle-cell anemia or cystic fibrosis if parents are each heterozygous for both.

A cell has enough available ATP to meet its needs for about 30 seconds. What is likely to happen when an athlete exhausts his or her ATP supply? A) He or she has to sit down and rest. B) Catabolic processes are activated that generate more ATP. C) ATP is transported into the cell from the circulatory system. D) Other cells take over, and the muscle cells that have used up their ATP cease to function.

Catabolic processes are activated that generate more ATP.

Which of the following molecules is a protein maintained at steady levels throughout the cell cycle that requires cyclin to become catalytically active? A) PDGF B) MPF C) cyclin D) Cdk

Cdk

Using data from the table above, select the best explanation for why that cell will be able to eliminate waste most efficiently? A) Cell 1, since it has the smallest volume and will not produce as much waste as the other cells. B) Cell 2, since it has the highest ratio of surface area to volume, which facilitates the exchange of materials between a cell and its environment. C) Cell 3, since it has the largest surface area, which will enable it to eliminate all of its wastes efficiently. D) Cell 3, because it is big enough to allow wastes to easily diffuse through the plasma membrane.

Cell 2, since it has the highest ratio of surface area to volume, which facilitates the exchange of materials between a cell and its environment.

Cells from advanced malignant tumors often have very abnormal chromosomes and an abnormal number of chromosomes. What might explain the association between malignant tumors and chromosomal abnormalities? A) Cancer cells are no longer density-dependent. B) Cancer cells are no longer anchorage-dependent. C) Cell cycle checkpoints are not in place to stop cells with chromosome abnormalities. D) Transformation introduces new chromosomes into cells.

Cell cycle checkpoints are not in place to stop cells with chromosome abnormalities.

How do cells use the ATP cycle illustrated in the figure? A) Cells use the cycle to recycle ADP and phosphate. B) Cells use the cycle to recycle energy released by ATP hydrolysis. C) Cells use the cycle to recycle ADP, phosphate, and the energy released by ATP hydrolysis. D) Cells use the cycle primarily to generate heat.

Cells use the cycle to recycle ADP and phosphate.

In what way do the membranes of a eukaryotic cell vary? A) Phospholipids are found only in certain membranes. B) Certain proteins are unique to each membrane. C) Only certain membranes of the cell are selectively permeable. D) Only certain membranes are constructed from amphipathic molecules.

Certain proteins are unique to each membrane.

Thylakoids, DNA, and ribosomes are all components found in ________. A) chloroplasts B) mitochondria C) lysosomes D) nuclei

Chloroplasts

If a horticulturist breeding gardenias succeeds in having a single plant with a particularly desirable set of traits, which of the following would be her most probable and efficient route to establishing a line of such plants? A) Backtrack through her previous experiments to obtain another plant with the same traits. B) Breed this plant with another plant with much weaker traits. C) Clone the plant. D) Force the plant to self-pollinate to obtain an identical one.

Clone the plant.

Which of the following processes occurs when homologous chromosomes cross over in meiosis I? A) Two sister chromatids get tangled, resulting in one re-sequencing its DNA. B) Two sister chromatids exchange identical pieces of DNA. C) Corresponding segments of non-sister chromatids are exchanged. D) Maternal alleles are "corrected" to be like paternal alleles and vice versa.

Corresponding segments of non-sister chromatids are exchanged.

What is the difference between covalent bonds and ionic bonds? A) Covalent bonds involve the sharing of pairs of electrons between atoms; ionic bonds involve the sharing of single electrons between atoms. B) Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between charged atoms. C) Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the sharing of protons between charged atoms. D) Covalent bonds involve the transfer of electrons between charged atoms; ionic bonds involve the sharing of electrons between atoms.

Covalent bonds involve the SHARING of electrons between atoms; ionic bonds involve the ELECTRICAL ATTRACTION between charged atoms

Which of the following occurrences describes how recombination between linked genes comes about? A) Nonrecombinant chromosomes break and then rejoin with one another. B) Independent assortment sometimes fails. C) Linked genes travel together at anaphase. D) Crossovers between these genes result in chromosomal exchange.

Crossovers between these genes result in chromosomal exchange.

Use your knowledge of the mechanism of photosynthesis and the data presented in the chart to determine which of the statements is a correct explanation for the students' data. A) Cup 1 had a low rate of photosynthesis because 0.5 grams of baking soda did not provide a sufficient amount of CO2. B) Cup 2 had the highest rate of photosynthesis because it had the highest ratio of disks floating to wattage of light. C) Cup 3 had the same rate of photosynthesis as Cup 1 because they had the same ratio of disks floating to wattage of light. D) Cup 4 had the lowest rate of photosynthesis because it had the least CO2.

Cup 4

You have just sequenced a new protein found in mice and observe that sulfur-containing cysteine residues occur at regular intervals. What is the significance of this finding? A) Cysteine residues are required for the formation of α helices and β pleated sheets. B) It will be important to include cysteine in the diet of the mice. C) Cysteine residues are involved in disulfide bridges that help form tertiary structure. D) Cysteine causes bends, or angles, to occur in the tertiary structure of proteins.

Cysteine residues are involved in disulfide bridges that help form tertiary structure.

Use the figure to answer the following question. In the late 1950s, Meselson and Stahl grew bacteria in a medium containing "heavy"; (radioactive) nitrogen (13N) and then transferred them to a medium containing 14N (non- radioactive). Which of the results in the figure would be expected after ONE ROUND of DNA replication in the presence of 14N?

Use the figures to answer the question. Which molecule shown above can contribute nNEGATIVE CHARGE when positioned in a chain? A) A B) B C) C D) D

Use the figures to answer the question. Which molecule shown above contains a functional group that is a part of the molecule known as the "ENERGY CURRENCY OF LIVING ORGANISMS";? A) A B) B C) C D) D

Use the figures to answer the question. Which of the functional groups shown helps stabilize proteins by forming covalent CROSS-LINKS within or between protein molecules? A) A B) B C) C D) D

Which component in the accompanying figure is CHOLESTEROL? A) B B) C C) D D) E

Which component in the accompanying figure is HYDROPHILIC? A) A B) B C) C D) D

How would acidification of seawater affect marine organisms? Acidification of seawater would ________. A) increase dissolved carbonate concentrations and promote faster growth of corals and shell- building animals B) decrease dissolved carbonate concentrations and promote faster growth of corals and shell- building animals C) increase dissolved carbonate concentrations and hinder growth of corals and shell-building animals D) decrease dissolved carbonate concentrations and hinder growth of corals and shell-building animals

DECREASE dissolved carbonate concentrations and HINDER growth of corals and shell-building animals

A DECREASE IN ENTROPY is associated with which type of reaction? A) dehydration B) catabolic C) depolymerization D) hydrolysis

DEHYDRATION

Hershey and Chase set out to determine what molecule served as the unit of inheritance. They completed a series of experiments in which E. coli was infected by a T2 virus. Which molecular component of the T2 virus actually ended up inside the cell? A) protein B) RNA C) ribosome D) DNA

DNA

Which component is NOT DIRECTLY INVOLVED in translation? A) GTP B) DNA C) tRNA D) ribosomes

DNA

A BIOCHEMIST ISOLATES, PURIFIES, AND COMBINES in a test tube a variety of molecules needed for DNA replication. When she adds some DNA to the mixture, replication occurs, but each DNA molecule consists of a normal strand paired with numerous segments of DNA a few hundred nucleotides long. What has she probably left out of the mixture? A) DNA polymerase B) DNA ligase C) Okazaki fragments D) primase

DNA LIGASE

In E. coli, which enzyme catalyzes the elongation of a new DNA strand in the 5' → 3' direction? A) primase B) DNA ligase C) DNA polymerase III D) helicase

DNA POLYMERASE III

What is the basis for the difference in how the leading and lagging strands of DNA molecules are synthesized? A) The origins of replication occur only at the 5′ end. B) Helicases and single-strand binding proteins work at the 5′ end. C) DNA polymerase can join new nucleotides only to the 3′ end of a pre-existing strand, and the strands are antiparallel. D) DNA ligase works only in the 3′ → 5′ direction.

DNA POLYMERASE can join new nucleotides only to the 3' end of a pre-existing strand, and the strands are ANTIPARALLEL

The lagging strand is characterized by a series of short segments of DNA (Okazaki fragments) that will be joined together to form a finished lagging strand. The experiments that led to the DISCOVERY OF OKAZAKI fragments gave evidence for which of the following ideas? A) DNA polymerase is an enzyme that synthesizes leading and lagging strands during replication only in one direction. B) DNA is a polymer consisting of four monomers: adenine, thymine, guanine, and cytosine. C) DNA is the genetic material. D) Bacterial replication is fundamentally different from eukaryotic replication. The key should not be way longer than the distractors.

DNA POLYMERASE is an ENZYME THAT SYNTHESIZES leading and lagging strands during replication only in one direction

Eukaryotic chromosomes are composed of which of the following MACROMOLECULESs? A) DNA and RNA B) DNA only C) DNA and proteins D) DNA and phospholipids

DNA and PROTEINS

Which of the following facts did Hershey and Chase make use of in trying to determine whether DNA or protein is the genetic material? A) DNA contains sulfur, whereas protein does not. B) DNA contains phosphorus, whereas protein does not. C) DNA contains nitrogen, whereas protein does not. D) DNA contains purines, whereas protein includes pyrimidines.

DNA contains PHOSPHORUS, whereas proteins do not

Suppose you are provided with an actively dividing culture of E. coli bacteria to which radioactive thymine has been added. What would happen if a cell replicates once in the presence of this radioactive base? A) One of the daughter cells, but not the other, would have radioactive DNA. B) Neither of the two daughter cells would be radioactive. C) All four bases of the DNA would be radioactive. D) DNA in both daughter cells would be radioactive.

DNA in BOTH DAUGHTER cells would be radioactive

The central rule of molecular biology states that ________. A) DNA is transcribed into RNA, which is translated into protein B) DNA is translated into protein C) DNA is translated into RNA, which is transcribed into protein D) RNA is transcribed into protein

DNA is transcribed into RNA, which is translated into protein

DNA contains the template needed to copy itself, but it has no catalytic activity in cells. What catalyzes the formation of PHOSPHODIESTER bonds between adjacent nucleotides in the DNA polymer being formed during DNA replication? A) ribozymes B) DNA polymerase C) ATP D) RNA primers

DNA polymerase

Why does a new DNA strand elongate only in the 5'to 3' direction during DNA replication? A) DNA polymerase begins adding nucleotides at the 5' end of the template. B) The polarity of the DNA molecule prevents addition of nucleotides at the 3' end. C) Replication must progress toward the replication fork. D) DNA polymerase can add nucleotides only to the free 3'; end.

DNA polymerase can ADD nucleotides only to the free 3' end

In DNA replication, the resulting daughter molecules contain one strand of the original parental DNA and one new strand. What is the explanation for this phenomenon? A) DNA replication is semiconservative. B) DNA replication is conservative. C) DNA replication is not conservative. D) RNA synthesis is conservative.

DNA replication is SEMICONSERVATIVE

Which of the following statements is the most CURRENT DESCRIPTION of a gene? A) a unit of heredity that causes formation of a phenotypic characteristic B) a DNA subunit that codes for a single complete protein C) a DNA sequence that is expressed to form a functional product: either RNA or polypeptide D) a discrete unit of hereditary information that consists of a sequence of amino acids

DNA sequence that is EXPRESSED to form a FUNCTIONAL PRODUCT either RNA or polypeptide

Cilia and flagella bend because of ________. A) conformational changes in ATP that thrust microtubules laterally B) a motor protein called radial spokes C) contraction by myosin D) a motor protein called dynein

DYNEIN

In some parts of Africa, the frequency of heterozygosity for the sickle-cell anemia allele is unusually high, presumably because this reduces the frequency of malaria. Such a relationship is related to which of the following? A) Mendel's law of independent assortment B) Mendel's law of segregation C) Darwin's explanation of natural selection D) the malarial parasite changing the allele

Darwin's explanation of natural selection

In every case, caterpillars that feed on oak flowers look like oak flowers. In every case, caterpillars that were raised on oak leaves looked like twigs. These results support which of the following hypotheses? A) The longer day lengths of summer trigger the development of twig-like caterpillars. B) Differences in air pressure, due to elevation, trigger the development of different types of caterpillars. C) Differences in diet trigger the development of different types of caterpillars. D) The differences are genetic. A female will either produce all flowerlike caterpillars or all twig-like caterpillars.

Differences in diet trigger the development of different types of caterpillars

Which of the following processes occur during meiosis but not mitosis? A) Haploid cells fuse to form diploid cells. B) Haploid cells multiply into more haploid cells. C) Diploid cells form haploid cells. D) A diploid cell combines with a haploid cell.

Diploid cells form haploid cells.

New biosensors, applied like a temporary tattoo to the skin, can alert serious athletes that they are about to "hit the wall" and will find it difficult to continue exercising. These biosensors monitor lactate, a form of lactic acid, released in sweat during strenuous exercise. Which of the statements below is the best explanation of why athletes would need to monitor lactate levels? A) During aerobic respiration, muscle cells cannot produce enough lactate to fuel muscle cell contractions, and muscles begin to cramp, thus athletic performance suffers. B) During anaerobic respiration, lactate levels increase when muscles cells need more energy; however, muscles cells eventually fatigue, thus athletes should modify their activities to increase aerobic respiration. C) During aerobic respiration, muscles cells produce too much lactate, which causes a rise in the pH of the muscle cells, thus athletes must consume increased amounts of sports drinks, high in electrolytes, to buffer the pH. D) During anaerobic respiration, muscle cells receive too little oxygen and begin to convert lactate to pyruvate (pyruvic acid), thus athletes experience cramping and fatigue.

During anaerobic respiration, lactate levels increase when muscles cells need more energy; however, muscles cells eventually fatigue, thus athletes should modify their activities to increase aerobic respiration.

Cells that are infected, damaged, or have reached the end of their functional life span often undergo "programmed cell death." This controlled cell suicide is called apoptosis. Select the appropriate description of this event on a cell's life cycle. A) Apoptosis is regulated by cell surface receptors that signal when a cell has reached its density-dependent limits. B) During apoptosis, dying cells leak out their contents, including digestive enzymes that also destroy healthy cells. C) During apoptosis, cellular agents chop up the DNA and fragment the organelles and other cytoplasmic components of a cell. D) Each cell organelle has protein signals that initiate the breakdown of the organelle's components, which leads to cell death.

During apoptosis, cellular agents chop up the DNA and fragment the organelles and other cytoplasmic components of a cell.

What is the correct chromosomal condition for one daughter nucleus at TELOPHASE of mitosis? A) B B) C C) D D) E

Which of the following statements is a logical CONSEQUENCE OF SECOND LAW of thermodynamics? A) If the entropy of a system increases, there must be a corresponding decrease in the entropy of the universe. B) If the entropy of a system decreases, there must be a corresponding decrease in the entropy of the universe. C) If there is an increase in the energy of a system, there must be a corresponding decrease in the energy of the rest of the universe. D) Each chemical reaction in an organism must increase the total entropy of the universe.

EACH chemical reaction in an organism must increase the TOTAL ENTROPY of the universe

Use the figure to answer the question. Refer to the metabolic pathway illustrated. If A, B, and C are all required for growth, a strain that is mutant for the gene-encoding enzyme (A) would be able to grow on medium supplemented with which of the following nutrient(s)? A) nutrient A only B) either nutrient B or C C) nutrient C only D) nutrients A and C

EITHER nutrient B or C

What is the explanation for how a modern transmission electron MICROSCOPE (TEM) can achieve a resolution of about 0.2 nanometers, whereas a standard light microscope has a maximum resolution of about 200 nanometers? A) Glass lenses in light microscopes refract light, which reduces resolution. B) Contrast is enhanced by staining with atoms of heavy metal. C) Electron beams have much shorter wavelengths than visible light. D) The electron microscope has a much greater ratio of image size to real size.

ELECTRON BEAMS have much shorter wavelength than visible light

The BEGINNING OF ANAPHASE is indicated by which of the following processes? A) Loss of kinetochores from the chromatids. B) Attachment of sister chromatids to each other by cohesin. C) Enzymatic cleavage of cohesin. D) Disappearance of the nuclear membrane.

ENZYMATIC CLEAVAGE of cohesion

What happens to the FREE ENERGY released as electrons are passed from photosystem II to photosystem I through a series of ELECTRON CARRIERS? A) It excites electrons of the reaction center in photosystem I. B) It is used to establish and maintain a proton gradient. C) It is used to synthesize ATP through substrate-level phosphorylation. D) It is used to phosphorylate NAD+ to NADPH.

ESTABLISH and MAINTAIN PROTON GRADIENT

Which of the following statements describes a characteristic feature of a carrier protein in a plasma membrane? A) It exhibits specificity for a particular type of molecule. B) It requires the expenditure of cellular energy to function. C) It works against diffusion. D) It has no hydrophobic regions.

EXHIBITS SPECIFICITY for a particular type of molecule

Which of the following is NOT TRUE OF RNA processing? A) Exons are cut out before mRNA leaves the nucleus. B) Nucleotides may be added at both ends of the RNA. C) Ribozymes may function in RNA splicing. D) RNA splicing can be catalyzed by spliceosomes.

EXONS are cut out before mRNA leaves the nucleus

Which of the following statements describes the process of transformation in bacteria? A) A strand of DNA is created from an RNA molecule. B) A strand of RNA is created from a DNA molecule. C) Bacterial cells are infected by a phage DNA molecule. D) External DNA is taken into a cell, becoming part of the cell's genome.

EXTERNAL DNA is taken into a cell, becoming part of the cell's genome

Which of the following statements describes one characteristic of each chromosome in a cell during the entire process of meiosis I? A) Each chromosome is paired with a homologous chromosome. B) Each chromosome consists of two sister chromatids joined by a centromere. C) Each chromosome consists of a single strand of DNA. D) Each chromosome is joined with its homologous pair to form a synaptonemal complex.

Each chromosome consists of two sister chromatids joined by a centromere.

Which of the following statements is true of a species that has a chromosome number of 2n = 16? A) The species is diploid with 32 chromosomes per cell. B) The species has 16 sets of chromosomes per cell. C) Each diploid cell has eight homologous pairs of chromosomes. D) A gamete from this species has four chromosomes.

Each diploid cell has eight homologous pairs of chromosomes.

A female with a paternal set of one orange and one long gene chromosome and a maternal set comprised of one blue and one short gene chromosome would be expected to produce which of the following types of eggs after meiosis? A) All eggs will have maternal types of gene combinations. B) All eggs will have paternal types of gene combinations. C) Half the eggs will have maternal and half will have paternal combinations. D) Each egg has a one-fourth chance of having either blue long, blue short, orange long, or orange short combinations.

Each egg has a one-fourth chance of having either blue long, blue short, orange long, or orange short combinations.

A gene for the MN blood group has codominant alleles M and N. If both children in a family are of blood type M, which of the following situations is possible? A) Each parent is either M or MN. B) Each parent must be type M. C) Both children are heterozygous for this gene. D) Neither parent can have the N allele.

Each parent is either M or MN.

Which of the following characteristics is most likely to be associated with an enzyme that catalyzes two different chemical reactions? A) The enzyme contains α-helices and β-pleated sheets. B) The enzyme is subject to competitive inhibition and allosteric regulation. C) The enzyme is composed of at least two subunits. D) Either the enzyme has two distinct active sites or the substrates involved in the two reactions have very similar structures.

Either the enzyme has two distinct active sites or the substrates involved in the two reactions have very similar structures.

Sutherland discovered that the signaling molecule epinephrine is responsible for which of the following events? A) Stimulating glycogen synthesis. B) Decreasing blood glucose levels. C) Interacting directly with glycogen phosphorylase. D) Elevating cytosolic concentrations of cyclic AMP.

Elevating cytosolic concentrations of cyclic AMP.

Which of the following statements about enzyme function is true? A) Enzyme function is generally increased if the three-dimensional structure or conformation of an enzyme is altered. B) Enzyme function is independent of physical and chemical environmental factors such as pH and temperature. C) Enzymes increase the rate of chemical reactions by lowering activation energy barriers. D) Enzymes increase the rate of chemical reactions by providing activation energy to the

Enzymes increase the rate of chemical reactions by lowering activation energy barriers.

Which of the following investigators was (were) responsible for the discovery that in DNA from any species, the amount of adenine equals the amount of thymine, and the amount of guanine equals the amount of cytosine? A) Alfred Hershey and Martha Chase B) Oswald Avery, Maclyn McCarty, and Colin MacLeod C) Erwin Chargaff D) Matthew Meselson and Franklin Stahl

Erwin Chargaff

At puberty, an adolescent female body changes in both structure and function of several organ systems, primarily under the influence of changing concentrations of estrogen and other steroid hormones. How can one hormone, such as estrogen, mediate so many effects? A) Estrogen is produced in very large concentration by nearly every tissue of the body. B) Each cell responds in the same way when steroids bind to the cell surface. C) Estrogen is kept away from the surface of any cells, not able to bind it at the surface. D) Estrogen binds to specific receptors inside many kinds of cells, each with different responses.

Estrogen binds to specific receptors inside many kinds of cells, each with different responses.

During aerobic respiration, which of the following molecules directly donates electrons to the electron transport chain at the lowest energy level? A) NADH B) ATP C) water D) FADH2

FADH2

Beta oxidation generates substrates for cellular respiration through which of the following processes? A) catabolism of glucose B) catabolism of glycogen C) catabolism of proteins D) catabolism of fatty acids

FATTY ACIDS

If the cell whose NUCLEAR MATERIAL is shown in the figure continues toward completion of mitosis, which of the following events would occur next? A) spindle fiber formation B) nuclear envelope breakdown C) formation of telophase nuclei D) synthesis of chromatids

FORMATION of TELOPHASE

An original section of DNA has the base sequence AGCGTTACCGT. A mutation in this DNA strand results in the base sequence AGGCGTTACCGT. What type of mutation does this change represent? A) a missense mutation B) a point mutation C) a silent mutation D) frameshift mutation

FRAMESHIFT mutation extra G

In which of the following ways do PLANT HORMONES differ from hormones in animals? A) Plant hormones frequently travel through the air as a gas. B) Animal hormones are only local regulators. C) Plant hormones commonly travel through the soil from one plant to another. D) Animal hormones typically travel from the hormone producing cell to an adjacent responding cell through gap junctions.

FREQUENTLY TRAVEL through AIR AS A GAS

A new organism is discovered in the forests of Costa Rica. Scientists there determine that the polypeptide sequence of hemoglobin from the new organism has 72 amino acid differences from humans, 65 differences from a gibbon, 49 differences from a rat, and 5 differences from a frog. These data suggest that the new organism is more closely related to ________. A) humans than to frogs B) frogs than to humans C) rats than to frogs D) gibbons than to rats

FROGS THAN TO HUMANS

One of the primary functions of RNA molecules is to ________. A) transmit genetic information to offspring B) function in the synthesis of proteins C) make a copy of itself, thus ensuring genetic continuity D) act as a pattern or blueprint to form DNA

FUNCTION OF THE SYNTHESIS OF PROTEINS

Hemoglobin, when subjected to 40% acetonitrile at pH 10.0, loses its quaternary structure, which means the ________. A) four α and β polypeptides dissociate B) peptide bonds between amino acids break C) α and β polypeptides lose their 3-D structure D) four α and β polypeptides dissociate, peptide bonds between amino acids, and α and β polypeptides lose their 3-D structure

Four α and β polypeptides dissociate

Which of the following statements about a G protein signaling pathway is true? A) A G protein-coupled receptor bound to GTP is in its active state. B) A G protein bound to GTP is in its active state. C) A G protein bound to GDP is in its active state. D) Hydrolysis of bound GTP by a G protein activates the G protein.

G protein bound to GTP

The data in the table were obtained from a study of the length of time spent in each phase of the cell cycle by cells of three eukaryotic organisms designated BETA DELTA GAMMA. What is the best explanation for the DATA ASSOCIATED with delta cells? A) Delta cells contain no DNA. B) Delta cells contain no RNA. C) Delta cells are in the G0 phase. D) Delta cells divide in the G1 phase.

G0 phase

Cell A has half as much DNA as cells B, C, and D in a mitotically active tissue. Cell A is most likely in A) G1. B) G2. C) prophase. D) metaphase.

Measurements of the amount of DNA per nucleus were taken on a large number of cells from a GROWING FUNGUS. The measured DNA levels ranged from 3 to 6 PICOGRAMS per nucleus. In which stage of the cell cycle did the nucleus contain 6 picograms of DNA? A) G1 B) S C) G2 D) G0

Which of the statements is the best explanation for the difference between TIME SPEND in S phase by BETA and GAMMA? A) Gamma contains more DNA than beta. B) Beta and gamma contain the same amount of DNA. C) Beta cells reproduce by binary fission and gamma cells reproduce by mitosis and cytokinesis. D) Beta is a plant cell and gamma is an animal cell.

GAMMA contains more DNA than beta

Which of the following statements correctly describes ARCHIBALD GARROD's hypothesis for how "inborn errors of metabolism" such as alkaptonuria occur? A) Metabolic enzymes require vitamin cofactors, and affected individuals have significant nutritional deficiencies. B) Enzymes are made of DNA, and affected individuals lack DNA polymerase. C) Certain metabolic reactions are carried out by ribozymes, and affected individuals lack key splicing factors. D) Genes dictate the production of specific enzymes, and affected individuals have genetic defects that cause them to lack certain enzymes.

GENES DICTATE the production of specific enzymes, and affected individuals have genetic defects that cause them to lack certain enzymes

Yeast cells that have defective mitochondria incapable of respiration will be able to grow by catabolizing which of the following carbon sources for energy? A) glucose B) cholesterol C) fatty acids D) amino acids

GLUCOSE

PAPER CHROMATOGRAPHY is a technique used to separate molecules based upon their size and solubility in a particular solvent. If pigments from a particular species of plant are extracted and subjected to paper chromatography, which of the following results is most likely? A) Paper chromatography would produce a single band of pigment that is characteristic of that particular plant. B) Paper chromatography would separate the pigments into two bands that appear green. C) Paper chromatography would separate the pigments into several bands that appear green or yellow/orange. D) Paper chromatography would separate the pigments into two bands, one that appears blue and one that appears red.

GREEN YELLOW/ORANGE

HALOBACTERIUM has a photosynthetic membrane that appears purple. Its photosynthetic action spectrum is the inverse of the action spectrum for green plants (see figure). That is, the Halobacterium action spectrum has a peak where the green plant action spectrum has a trough. What wavelengths of light do the Halobacterium photosynthetic pigments absorb? A) red and yellow B) violet and blue C) green and yellow D) blue and red

GREEN and YELLOW

Which of the following is a correct association? A) kinase activity and the addition of a tyrosine B) phosphodiesterase activity and the removal of phosphate groups C) GTPase activity and hydrolysis of GTP to GDP D) adenylyl cyclase activity and the conversion of cAMP to AMP

GTPase activity and hydrolysis of GTP to GDP

Characters are transmitted from parents to offspring. ________ are the units of inheritance. A) Genes B) Proteins C) RNA D) DNA

Genes

Use the following information to answer the question. A plantlike organism on the planet Pandora can have three recessive genetic traits: bluish leaves, due to an allele (a) of gene A; a feathered stem, due to an allele (b) of gene B; and hollow roots due to an allele (c) of gene C. The three genes are linked and recombine. A geneticist performed a testcross with an organism that had been found to be heterozygous for the three recessive traits, and she was able to identify progeny of the following phenotypic distribution (+ = wild type): Phenotypes Leaves Stems Roots Number 1 a + + 14 2 a + c 0 3 a b + 32 4 a b c 440 5 + b + 0 6 + b c 16 7 + + c 28 8 + + + 470 Total 1000 The greatest distance among the three genes is between a and c. What does this mean? A) Gene c is between a and b. B) Genes are in the order: a-b-c. C) Gene a is not recombining with c. D) Gene a is between b and c.

Genes are in the order: a-b-c.

The somatic cells of a privet shrub each contain a total of 46 chromosomes. How do the chromosomes of this plant differ from the chromosomes of humans, who also have a total of 46? A) Privet shrub cells cannot reproduce sexually. B) Privet shrub sex cells have chromosomes that can synapse with human chromosomes in the laboratory. C) Genes of privet shrub chromosomes are significantly different than those in humans. D) Privet shrubs must be metabolically more like animals than like other shrubs.

Genes of privet shrub chromosomes are significantly different than those in humans.

Gray seed color in peas is dominant to white. Assume that Mendel conducted a series of experiments where plants with gray seeds were crossed among themselves, and the following progeny were produced: 302 gray and 98 white. What is the most probable genotype of each parent? A) GG × gg B) Gg × Gg C) GG × Gg D) gg × Gg

Gg × Gg

Which observation suggested to Sutherland the involvement of a second messenger in epinephrine's effect on liver cells? A) Enzymatic activity was proportional to the amount of calcium added to a cell-free extract. B) Receptor studies indicated that epinephrine was a ligand. C) Glycogen breakdown was observed only when epinephrine was administered to intact cells. D) Glycogen breakdown was observed only when epinephrine and glycogen phosphorylase were mixed.

Glycogen breakdown was observed only when epinephrine was administered to intact cells.

Which of the following organelles produces and modifies polysaccharides that will be secreted? A) lysosome B) mitochondrion C) Golgi apparatus D) peroxisome

Golgi apparatus

A mutation that disrupts the ability of an animal cell to add polysaccharide modifications to proteins would most likely cause defects in which of the following organelles or structures? A) nuclear matrix and extracellular matrix B) mitochondria and Golgi apparatus C) Golgi apparatus and extracellular matrix D) nuclear pores and secretory vesicles

Golgi apparatus and extracellular matrix

A scientist, who wants to study the effects of nitrogen on wheat plants, sets up an experiment with 4 groups of wheat plants: group A gets 20 pounds per acre, group B gets 40 pounds per acre, group C gets 60 pounds per acre, and group D gets 0 pounds per acre. Which of the following is the control group? A) group A B) group B C) group C D) group D

Group D

In research on aging (both cellular aging and organismal aging), it has been found that aged cells do not progress through the cell cycle as they had previously. Which of the following, if found in cells or organisms as they age, would provide evidence that this is related to cell signaling? A) Growth factor ligands do not bind as efficiently to receptors. B) Hormone concentrations decrease. C) cAMP levels change very frequently. D) Enzymatic activity declines.

Growth factor ligands do not bind as efficiently to recepto

The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the A) oxidation of glucose and other organic compounds. B) flow of electrons down the electron transport chain. C) H+ concentration gradient across the membrane holding ATP synthase. D) transfer of phosphate to ADP.

H+ concentration gradient across the membrane holding ATP synthase

Which of the following sequences correctly represents the FLOW OF ELECTRONS during photosynthesis? A) NADPH → O2 → CO2 B) H2O → NADPH → Calvin cycle C) NADPH → chlorophyll → Calvin cycle D) NADPH → electron transport chain → O2

H20

Which of the pairs of molecular structures shown depict enantiomers (enantiomeric forms) of the same molecule?

H2N on the LEFT

Which of the following are compounds? A) H2O, O2, and CH4 B) H2O and O2 C) O2 and CH4 D) H2O and CH4, but not O2

H2O and CH4 but not O2

Which of the following sequences correctly represents the flow of electrons during photosynthesis? A) NADPH → O2→ CO2 B) H2O → NADPH → Calvin cycle C) H2O → photosystem I → photosystem II D) NADP → Helectron transport chain → O2

H2O → NADPH → Calvin cycle

The atomic number of sulfur is 16. Sulfur combines with hydrogen by covalent bonding to form a compound, hydrogen sulfide. Based on the number of valence electrons in a sulfur atom, predict the molecular formula of the compound. A) HS B) HS2 C) H2S D) H4S

H2S

Low humidity in the atmosphere on a hot day ________. A) helps in cooling because skin absorbs water from the atmosphere B) does not help in cooling because water evaporates from the skin faster C) helps in cooling because water evaporates from the skin faster D) does not help in cooling because skin absorbs water from the atmosphere

HELPS in cooling because water EVAPORATES from the skin faster

The molecule shown is ________. A) a hexose B) a pentose C) fructose D) maltose

HEXOSE

In a nucleosome, the DNA IS WRAPPED around A) histones. B) ribosomes. C) polymerase molecules. D) a thymine dimer.

HISTONES

A sexually reproducing animal has two unlinked genes, one for head shape (H) and one for tail length (T). Its genotype is HhTt. Which of the following genotypes is possible in a gamete from this organism? A) Hh B) HhTt C) T D) HT

What type of bonding is responsible for MAINTAINING THE SHAOPE OF tRNA molecule shown in the figure? A) ionic bonding between phosphates B) hydrogen bonding between base pairs C) van der Waals interactions between hydrogen atoms D) peptide bonding between amino acids

HYDROGEN BONDING

What element does not prefer to react with other elements? A) hydrogen B) helium C) beryllium D) both hydrogen and beryllium

Helium

A young dog has never had much energy. He is brought to a veterinarian for help, and she decides to conduct several diagnostic tests. She discovers that the dog's mitochondria can use only fatty acids and amino acids for respiration, and his cells produce more lactate than normal. Of the following, which is the best explanation of the dog's condition? A) His mitochondria lack the transport protein that moves pyruvate across the outer mitochondrial membrane. B) His cells cannot move NADH from glycolysis into the mitochondria. C) His cells lack the enzyme in glycolysis that forms pyruvate. D) His cells have a defective electron transport chain, so glucose is metabolized to lactate instead of to acetyl CoA.

His mitochondria lack the transport protein that moves pyruvate across the outer mitochondrial membrane.

Which of the following events happens at the conclusion of meiosis I? A) Homologous chromosomes of a pair are separated from each other. B) The chromosome number per cell remains the same. C) Sister chromatids are separated. D) Four daughter cells are formed.

Homologous chromosomes of a pair are separated from each other.

Which of the following questions is considered a thought-provoking scientific query? A) How long ago did the Pterosaurs live on this planet? B) Does the amount of solute in water affect the boiling point of the solution? C) Who invented the telescope? D) How many tigers are left in India?

How many tigers are left in India?

Which of these is an example of inductive reasoning? A) Hundreds of individuals of a species have been observed and all are photosynthetic; therefore, the species is photosynthetic. B) These organisms live in sunny regions. Therefore, they are using photosynthesis. C) If protists are all single-celled, then they are incapable of aggregating. D) If two species are members of the same genus, they are more alike than each of them could be to a different genus.

Hundreds of individuals of a species have been observed and all are photosynthetic; therefore, the species is photosynthetic

Why do hydrolysis reactions occur more readily in solution than dehydration reactions? A) Hydrolysis reactions increase G, or Gibbs free energy of the system. B) Hydrolysis reactions are endergonic and increase entropy of the system. C) Hydrolysis reactions are exergonic and decrease entropy of the system. D) Hydrolysis reactions are exergonic and increase entropy of the system.

Hydrolysis reactions are exergonic and increase entropy of the system.

Which of the following statements best distinguishes hypotheses from theories in science? A) Theories are hypotheses that have been proved. B) Hypotheses are guesses; theories are correct answers. C) Hypotheses usually are relatively narrow in scope; theories have broad explanatory power. D) Theories are proved true; hypotheses are often contradicted by experimental results.

Hypotheses usually are relatively narrow in scope theories have a broad explanatory power

DNA was isolated from three different cell types of the same organism, the relative DNA content for each type was determined, and the results were plotted on the graph shown in the figure below. Refer to the graph to answer the following questions. 35) Which sample of DNA might be from a cell that stopped the process of cell division in G0 phase of the cell cycle prior to meiosis? A) I B) II C) III D) either I or II

Refer to the drawings in the figure below of a single pair of homologous chromosomes as they might appear during various stages of either mitosis or meiosis, and answer the following question(s). 33) Which diagram represents anaphase I of meiosis? A) I B) II C) IV D) V

Which sample of DNA might represent a zygote? A) I B) II C) III D) either I or II

In the figure, G1 is represented by which numbered part(s) of the cycle? A) I and V B) II C) III D) IV

I V

Refer to the life cycles illustrated in the figure below to answer the following questions. 15) Which of the life cycles is typical for animals? A) I only B) II only C) III only D) I and III

I only

For the following questions, match the key event of meiosis with the stages listed below. I. Prophase I V. Prophase II II. Metaphase I VI. Metaphase II III. Anaphase I VII. Anaphase II IV. Telophase I VIII. Telophase II 31) Homologous chromosomes are aligned at the equator of the spindle. A) I B) II C) IV D) VI

In the figure, which number represents DNA SYNTHESIS? A) I B) II C) III D) IV

Which sample of DNA might represent an animal cell in the G2 phase of the cell cycle prior to meiosis? A) I B) II C) III D) both I and II

Which of the life cycles is typical for most fungi and some protists? A) I only B) II only C) III only D) I and II

II only

Eukaryotic sexual life cycles show tremendous variation. Which of the following characteristics do all sexual life cycles have in common? I. Alternation of generations II. Meiosis III. Fertilization IV. Gametes V. Spores A) I, II, and IV B) II, III, and IV C) II, IV, and V D) I, II, III, IV, and V

II, III, and IV

In the figure, at which of the numbered regions would you expect to find cells at METAPHASE? A) II and IV B) II only C) III only D) IV only

III ONLY

Which of the life cycles is typical for plants and some algae? A) I only B) II only C) III only D) I and III

III only

To identify the molecule that accepts CO2, Calvin and BENSON manipulated the carbon- fixation cycle by either cutting off CO2 or cutting off light from cultures of photosynthetic algae. They then measured the concentrations of various metabolites immediately following the manipulation. How would these experiments help identify the CO2 acceptor? A) The CO2 acceptor concentration would decrease when either the CO2 or light are cut off. B) The CO2 acceptor concentration would increase when either the CO2 or light are cut off. C) The CO2 acceptor concentration would decrease when the CO2 is cut off, but increase when the light is cut off. D) The CO2 acceptor concentration would increase when the CO2 is cut off, but decrease when the light is cut off.

INCREASE when only CO2 is cut off

As the [H3O+] of the solution decreases, the [OH-] ________. A) increases and thus pH increases B) increases and thus pH decreases C) decreases and thus the pH decreases D) decreases and thus the pH increases

INCREASES and thus pH INCREASES

The membranes of WINTER WHEAT are able to remain fluid when it is extremely cold by ________. A) increasing the proportion of unsaturated phospholipids in the membrane B) decreasing the percentage of cholesterol molecules in the membrane C) decreasing the number of hydrophobic proteins in the membrane D) increasing the proportion of glycolipids in the membrane

INCREASING proportion of UNSATURATED phospholipids in the membrane

In autotrophic BACTERIA, where is CHLOROPHYLL located? A) in chloroplast membranes B) in the cell wall C) in the nucleoid D) in infolded regions of the plasma membrane

INFOLDED regions of the PLASMA MEMBRANE

Scientists have found that extracellular matrix components may induce specific gene expression in embryonic tissues such as the liver and testes. For this to happen, there must be direct communication between the extracellular matrix and the developing cells. Which kind of transmembrane protein would most likely be involved in this kind of induction? A) integrins B) fibronectins C) actin microfilaments D) receptor tyrosine kinases

INTEGRINS

What is the relationship between the WAVELENGTH OF LIGHT and the QUANTITY OF ENERGY per photon? A) They have a direct, linear relationship. B) They are inversely related. C) They are logarithmically related. D) They are separate phenomena.

INVERSELY RELATED

Which of the following statements correctly describes the normal tonicity conditions for typical plant and animal cells? The animal cell is in ________. A) a hypotonic solution, and the plant cell is in an isotonic solution B) an isotonic solution, and the plant cell is in a hypertonic solution C) a hypertonic solution, and the plant cell is in an isotonic solution D) an isotonic solution, and the plant cell is in a hypotonic solution

ISO HYPO

Which sentence best describes the logic of scientific inquiry? A) If I generate a testable hypothesis, tests and observations will support it. B) If my prediction is correct, it will lead to a testable hypothesis. C) If my observations are accurate, they will support my hypothesis. D) If my hypothesis is correct, I can expect certain test results.

If my hypothesis is correct, I can expect certain test results

Particular receptor tyrosine kinases (RTKs) that promote excessive cell division are found at high levels in various cancer cells. HER2 is an RTK that is present at excessively high levels in some breast cancer cells. Herceptin is a protein that binds to HER2 and inhibits cell division. Herceptin may be an effective treatment for breast cancer treatment under which of the following conditions? A) If injection of HER2 in the patient's cancer cells stimulates cell division. B) If the patient's cancer cells have excessive levels of HER2. C) If the patient's genome codes for the HER2. D) If the patient has excessive levels of other RTKs in cancer cells.

If the patient's cancer cells have excessive levels of HER2.

In eukaryotes, genetic information is passed to the next generation by processes that include mitosis or meiosis. Which of the following explanations correctly identifies the process and supports the claim that heritable information is passed from one generation to another? A) During mitosis, DNA replication occurs twice within the cell cycle to insure a full set of chromosomes within each of the daughter cells produced. B) Mitosis, followed by cytokinesis, produces daughter cells that are genetically different from the parent cell, thus insuring variation within the population. C) In asexual reproduction, a single individual is the sole parent and passes copies of its genes to its offspring without the fusion of gametes. D) Single-celled organisms can fuse their cells, reproducing asexually through mitosis to form new cells that are not identical to the parent cell.

In asexual reproduction, a single individual is the sole parent and passes copies of its genes to its offspring without the fusion of gametes.

Which of the following scenarios describes an example of epistasis? A) Recessive genotypes for each of two genes (aabb) results in an albino corn snake. B) In rabbits and many other mammals, one genotype (ee) prevents any fur color from developing. C) In Drosophila (fruit flies), white eyes can be due to an X-linked gene or to a combination of other genes. D) In cacti, there are several genes for the type of spines.

In rabbits and many other mammals, one genotype (ee) prevents any fur color from developing.

Which of the following statements is correct in comparing sexual and asexual reproduction? A) Asexual reproduction, but not sexual reproduction, is characteristic of only plants and fungi. B) In sexual reproduction, individuals transmit half of their nuclear genes to each of their offspring. C) In asexual reproduction, offspring are produced by fertilization without meiosis. D) Asexual reproduction produces only haploid offspring.

In sexual reproduction, individuals transmit half of their nuclear genes to each of their offspring.

A controlled experiment ________. A) is repeated many times to ensure that the results are accurate B) includes at least two groups, one of which does not receive the experimental treatment C) includes at least two groups, one differing from the other by two or more variables D) includes one group for which the scientist controls all variables

Includes at least two groups, one of which does not receive experimental treatment

Why does testosterone, a lipid-soluble signaling molecule that crosses the membranes of all cells, affect only target cells? A) Only target cells retain the appropriate genes regulated by testosterone. B) Intracellular receptors for testosterone are present only in target cells. C) Only target cells possess the cytosolic enzymes that transduce the signal from testosterone to adenylyl cyclase. D) Only in target cells is testosterone able to initiate the phosphorylation cascade leading to activated transcription factor.

Intracellular receptors for testosterone are present only in target cells.

What is the most likely mechanism by which testosterone functions inside a cell? A) It acts as a signal receptor that activates tyrosine kinases. B) It binds with a receptor protein that enters the nucleus and activates expression of specific genes. C) It acts as a steroid signal receptor that activates ion channel proteins in the plasma membrane. D) It coordinates a phosphorylation cascade that reduces spermatogenesis.

It binds with a receptor protein that enters the nucleus and activates expression of specific genes.

Which of the following statements is correct regarding the human X chromosomes? A) It is present in every somatic cell of males and females. B) It is the same size as other chromosomes and has the same number of genes. C) It carries genes that determine an individual's biological sex. D) It is referred to as an autosome.

It carries genes that determine an individual's biological sex.

Which of the following is a primary function of the active site of an enzyme? A) It binds allosteric regulators of the enzyme. B) It binds noncompetitive inhibitors of the enzyme. C) It catalyzes the reaction associated with the enzyme. D) It is activated by the presence of the end product of the metabolic pathway in which the enzyme is involved.

It catalyzes the reaction associated with the enzyme.

Which of the following statements about the electron transport chain is true? A) It is driven by ATP hydrolysis. B) It includes a series of hydrolysis reactions associated with mitochondrial membranes. C) It consists of a series of redox reactions D) It occurs in the cytoplasm of both prokaryotic and eukaryotic cells.

It consists of a series of redox reactions

Why is glycolysis considered to be one of the first metabolic pathways to have evolved? A) It produces much less ATP than does oxidative phosphorylation. B) It does not involve organelles or specialized structures, does not require oxygen, and is present in most organisms. C) It is present in prokaryotic cells but not in eukaryotic cells. D) It requires the presence of membrane-enclosed cell organelles found only in eukaryotic cells.

It does not involve organelles or specialized structures, does not require oxygen, and is present in most organisms.

If a cell has completed meiosis I and the first cytokinesis, and is just beginning meiosis II, which of the following is an appropriate description of its genetic contents? A) It has half the amount of DNA as the cell that began meiosis. B) It has half the chromosomes but twice the DNA of the parent cell. C) It has one-fourth the DNA and one-half the chromosomes as the parent cell. D) It is genetically identical to another cell formed from the same meiosis I event.

It has half the amount of DNA as the cell that began meiosis.

Which of the following statements about the evolution of life on Earth, from simple prokaryote-like cells to multicellular eukaryotic organisms, is true? A) By resulting in such diversity and complexity of life, it is an exception to the second law of thermodynamics. B) It has occurred in accordance with the laws of thermodynamics and resulted in a substantial increase in the entropy of the planet. C) It has occurred in accordance with the laws of thermodynamics and resulted in a substantial increase in the total energy in the universe. D) It has occurred in accordance with the laws of thermodynamics and resulted in a substantial decrease in the entropy of the planet.

It has occurred in accordance with the laws of thermodynamics and resulted in a substantial decrease in the entropy of the planet.

If an atom has a charge of +1, which of the following must be true? A) It has two more protons than neutrons. B) It has the same number of protons as electrons. C) It has one more electron than it does protons. D) It has one more proton than it does electrons.

It has one more proton than it does electrons

In liver cells, the inner mitochondrial membranes are about five times the area of the outer mitochondrial membranes. What purpose must this serve? A) It allows for an increased rate of glycolysis. B) It allows for an increased rate of the citric acid cycle. C) It increases the surface for oxidative phosphorylation. D) It increases the surface for substrate-level phosphorylation.

It increases the surface for oxidative phosphorylation.

In a Drosophila experiment, a cross was made between homozygous wild-type females and yellow-bodied males. All of the resulting F1s were phenotypically wild type. However, adult flies of the F2 generation (resulting from matings of the F1s) had the characteristics shown in the figure. How is the mutant allele for yellow body inherited? A) It is not X-linked. B) It is X-linked. C) It is inherited by X inactivation. D) It is Y-linked.

It is X-linked.

A 0.01 M solution of a substance has a pH of 2. What can you conclude about this substance? A) It is a strong acid that dissociates completely in water. B) It is a strong base that dissociates completely in water. C) It is a weak acid. D) It is a weak base.

It is a STRONG ACID that dissociates completely in water

An organism is discovered that thrives in both the presence and absence of oxygen. Interestingly, as oxygen is removed from the organism's environment, the rate of sugar consumption increases while the growth rate decreases. What do these observations suggest about the likely identity of this organism? A) It is an unremarkable eukaryotic organism. B) It is a photosynthetic organism. C) It is an obligate anaerobic organism. D) It is a facultative anaerobic organism.

It is a facultative anaerobic organism.

Which of the following statements correctly describes a karyotype? A) It is a display of all of the cell types in an organism. B) It is an organized image of a cell's chromosomes. C) It reveals the appearance of an organism. D) It is a display of a cell's mitotic stages.

It is an organized image of a cell's chromosomes.

When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated? A) It is used to power yet more cellular work. B) It is captured to store energy as more ATP. C) It is used to generate ADP from nucleotide precursors. D) It is lost to the environment.

It is lost to the environment.

Marfan syndrome in humans is caused by an abnormality of the connective tissue protein fibrillin. Patients are usually very tall and thin, with long spindly fingers, curvature of the spine, sometimes weakened arterial walls, and sometimes eye problems, such as lens dislocation. Which of the following would you conclude about Marfan syndrome from this information? A) It is recessive. B) It is dominant. C) It is pleiotropic. D) It is epistatic.

It is pleiotropic.

Characterization of the complete three-dimensional structure of a newly purified protein suggests that it catalyzes the breakdown of a large substrate. The protein consists of a single polypeptide chain. It has a large pocket that appears to be the binding site for the substrate and a smaller indentation that appears to be the binding site for a regulatory molecule. What do these structural observations suggest about the mechanism by which the activity of this protein is likely regulated? A) It is probably an enzyme that is regulated by noncompetitive inhibition. B) It is probably a multi-subunit enzyme that is regulated by allosteric regulation. C) It is probably an enzyme that is regulated by competitive inhibition. D) It is probably an enzyme that is regulated by cooperativity.

It is probably an enzyme that is regulated by noncompetitive inhibition.

In a Drosophila experiment, a cross was made between homozygous wild-type females and yellow-bodied males. All of the resulting F1s were phenotypically wild type. However, adult flies of the F2 generation (resulting from matings of the F1s) had the characteristics shown in the figure. How is the mutant allele for yellow body inherited? A) It is recessive. B) It is codominant. C) It is dominant. D) It is incompletely dominant.

It is recessive.

Which of the following best describes a model organism? A) It is often pictured in textbooks and is easy for students to imagine. B) It is well studied, it is easy to grow, and results are widely applicable. C) It is small, inexpensive to raise, and lives a long time. D) It has been chosen for study by early biologists.

It is well studies, easy to grow, and results are widely applicable

When ATP releases some energy, it also releases inorganic phosphate. What happens to the inorganic phosphate in the cell? A) It is secreted as waste. B) It is used only to regenerate more ATP. C) It may be used to form a phosphorylated intermediate. D) It enters the nucleus to be incorporated in

It may be used to form a phosphorylated intermediate.

How does the toxin of Vibrio cholerae cause profuse diarrhea? A) It modifies a G protein involved in regulating salt and water secretion. B) It modifies adenylyl cyclase and triggers excess formation of cAMP. C) It signals IP3 to act as a second messenger for the release of calcium. D) It modifies a ligand-gated ion channel.

It modifies a G protein involved in regulating salt and water secretion.

In the nematode C. elegans, ced-9 prevents apoptosis in a normal cell in which of the following ways? A) It prevents the caspase activity of ced-3 and ced-4. B) Ced-9 remains inactive until it is signaled by ced-3 and other caspases. C) Ced-9 cleaves to produce ced-3 and ced-4. D) Ced-9 prevents blebbing by its action on the cell membrane.

It prevents the caspase activity of ced-3 and ced-4.

A particular organism has 46 chromosomes in its karyotype. Which of the following statements is correct regarding this organism? A) It must be human. B) It must be an animal. C) It reproduces sexually. D) It produces gametes with 23 chromosomes

It produces gametes with 23 chromosomes

Which of the following is true of natural selection? A) It requires genetic variation. B) It results in descent with modification. C) It involves differential reproductive success. D) It requires genetic variation, results in descent with modification, and involves differential reproductive success.

It requires genetic variation, results in decent with modification, and involves differential reproductive success

Which of the following statements best describes the primary role played by oxygen in cellular respiration? A) It yields energy in the form of ATP as it is passed down the electron transport chain. B) It oxidizes glucose to form two molecules of pyruvate. C) It serves as an acceptor for carbon, forming CO2 in the citric acid cycle. D) It serves as the final acceptor for electrons from the electron transport chain.

It serves as the final acceptor for electrons from the electron transport chain.

A person on a strict diet and exercise regimen lost 7 kg (about 15 pounds) of body fat in just two weeks. What is the most likely way that the lost fat left the body? A) It was released as CO2 and H2O. B) It was converted to heat and then released. C) It was converted to ATP, which weighs much less than fat. D) It was eliminated from the body as feces.

It was released as CO2 and H2O.

Consider the following reaction at equilibrium: CO2 + H2OH2CO3. What would be the effect of adding additional H2O? A) It would drive the equilibrium dynamics to the right. B) It would drive the equilibrium dynamics to the left. C) Nothing would happen because the reactants and products are in equilibrium. D) Reactions in both the directions will slow down.

It would drive the equilibrium to the right

If an animal cell suddenly lost the ability to produce GTP, what might happen to its signaling system? A) It would not be able to activate G proteins on the cytoplasmic side of the plasma membrane. B) It would be able to carry out reception and transduction but would not be able to respond to a signal. C) It would use ATP instead of GTP to activate G proteins on the cytoplasmic side of the plasma membrane. D) It would not be able to activate receptor tyrosine kinases.

It would not be able to activate G proteins on the cytoplasmic side of the plasma membrane.

Which of the following statements is true regarding the complexity of biological systems? A) An understanding of the interactions between different components within a living system is an approach towards understanding reductionism. B) Knowing the function of a component of a living system can provide insights into the structure and organization of the living system. C) Understanding the chemical structure of DNA reveals how it directs the functioning of a living cell. D) An ecosystem displays complex properties of the biotic component only.

Knowing the function of a component of a living system can provide insights of structure into the system

Besides the ability of some cancer cells to over proliferate, which of the following situations might logically result in a tumor? A) changes in the order of cell cycle stages B) lack of appropriate cell death C) inability to form spindles D) failure of cells to enter S phase

LACK OF CELL DEATH

At what stage of the cell cycle is the cyclin component of MPF destroyed? A) in late G1 B) at mid-S phase C) in early G2 D) in late M

LATE M

Familial hypercholesterolemia is characterized by ________. A) defective LDL receptors on the cell membranes B) poor attachment of the cholesterol to the extracellular matrix of cells C) a poorly formed lipid bilayer that cannot incorporate cholesterol into cell membranes D) inhibition of the cholesterol active transport system in red blood cells

LDL

Binding of a signaling molecule to which type of receptor leads directly to a change in the distribution of substances on opposite sides of the membrane? A) intracellular receptor B) G protein-coupled receptor C) phosphorylated receptor tyrosine kinase dimer D) ligand-gated ion channel

LIGAND

In a plant, which of the following reactions produce MOLECULAR OXYGEN (O2)? A) the light reactions alone B) the Calvin cycle alone C) the light reactions and the Calvin cycle D) neither the light reactions nor the Calvin cycle

LIGHT REACTIONS ALONE

Which of the following graphs describes the relationship between [H3O+] and pH?

LOG curve decreasing

Which of the following statements describes what happens to a molecule that functions as the REDUCING AGENT (electron donor) in a redox or oxidation-reduction reaction? A) It gains electrons and gains potential energy. B) It loses electrons and loses potential energy. C) It gains electrons and loses potential energy. D) It loses electrons and gains potential energy.

LOSES e- LOSES potential energy

Which of the following statements is true for lipids? A) Lipids are true polymers. B) Waxes and pigments are not lipids. C) Lipids mix poorly with water. D) Lipids are true polymers and mix poorly with water.

Lipids mix poorly with water.

Recall that in the experiment, caterpillars born in the spring looked like flowers, and caterpillars born in the summer looked like twigs. What is the most likely selective advantage for this difference in body shape? A) Looking like their food sources allows the caterpillars to move through their environment more efficiently. B) Development into the adult moth form is faster for caterpillars shaped like twigs than like flowers. C) Looking like their food source lets the caterpillars blend into their surroundings, reducing predation. D) Looking like their food source will increase the caterpillars' feeding efficiency; this would increase their growth rate and survival rate.

Looking like their food source lets the caterpillars blend into their surroundings, reducing predation

Why are carbohydrates and fats frequently considered HIGH ENERGY FOODS? A) They contain many oxygen atoms. B) They contain no nitrogen atoms. C) They contain many electrons associated with hydrogen atoms. D) They are strong oxidizing molecules.

MANY ELECTRONS associated with HYDROGEN ATOMS

Which of the following is a major difference between prokaryotic cells and eukaryotic cells? A) Prokaryotic cells have cell walls, while eukaryotic cells do not. B) Eukaryotic cells have flagella, while prokaryotic cells do not. C) Eukaryotic cells have membrane-bound organelles, while prokaryotic cells do not. D) Prokaryotic cells are generally larger than eukaryotic cells.

MEMBRANE BOUND ORGANELLES prokaryotes do not

Once researchers identified DNA as the molecule responsible for transmitting heritable traits, they asked how information was transferred from the DNA in the nucleus to the site of protein synthesis in the cytoplasm. Which of the following statements correctly describes the MECHANISM OF INFORMATION TRANSFER IN EUKARYOTES that accomplishes this task? A) DNA from a single gene is replicated and transferred to the cytoplasm, where it serves as a template for protein synthesis. B) Messenger RNA is transcribed from a single gene and transfers information from the DNA in the nucleus to the cytoplasm, where protein synthesis takes place. C) Histone proteins in the chromosomes transfer information from the nucleus to the ribosome, where protein synthesis takes place. D) Transfer RNA takes information from DNA directly to a ribosome, where protein synthesis takes place.

MESSENGER RNA is transcribed from a single gene and transfers information from the DNA in the nucleus to the cytoplasm, where protein synthesis takes place

The M phase checkpoint ensures that all chromosomes are attached to the mitotic spindle. If this does not happen, cells would most likely be arrested in ________. A) telophase B) prophase C) G2 D) metaphase

METAPHASE

Which of the functional groups is not reactive but serves as a RECOGNIZABLE TAG on the DNA molecule and alter the expression of genes in the cells. A) amino B) methyl C) carboxyl D) hydroxyl

METHYL

Use the figure to answer the question. Thalidomide and L-dopa (see figure) are examples of PHARMACEUTICAL DRUGS that occur as ENANTIOMERS, or molecules that ________. A) have identical three-dimensional shapes B) are mirror images of one another C) are mirror images of one another and have the same biological activity D) are cis-trans isomers

MIRROR images of one another NOT same biological activity

Cyanide binds with at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the bound cyanide is likely to be localized within the ________. A) mitochondria B) peroxisomes C) lysosomes D) smooth endoplasmic reticulum

MITOCHONDRIA

Suppose a young boy is always tired and fatigued, suffering from a metabolic disease. Which of the following organelles is most likely malfunctioning in this disease? A) lysosomes B) Golgi apparatus C) mitochondria D) smooth endoplasmic reticulum

MITOCHONDRIA

Which of the following is the SMALLEST structure that would most likely be visible with a standard (not super-resolution) research-grade light MICROSCOPE? A) mitochondrion B) microtubule C) ribosome D) virus

MITOCHONDRIAN

TAXOL is an anticancer drug extracted from the PACIFIC EW TREE. In animal cells, Taxol prevents microtubule depolymerization. Thus, Taxol stops mitosis by interfering with which of the following structures or processes? A) the mitotic spindle B) cytokinesis C) centriole duplication D) chromosome condensation

MITOTIC SPINDLE

A SPACESHIP is designed to support animal life for a multiyear voyage to the outer planets of the solar system. Plants will be grown to provide oxygen and to recycle carbon dioxide. Since the spaceship will be too far from the sun for photosynthesis, an artificial light source will be needed. What wavelengths of light should be used to maximize plant growth with a minimum of energy expenditure? A) full-spectrum white light B) green light C) a mixture of blue and red light D) UV light

MIXTURE of BLUE and RED

What would be a likely consequence of a MUTATION IN PLANTS that results in a photorespiration deficiency? A) Photosynthetic efficiency would be reduced at low light intensities. B) Cells would carry on the Calvin cycle at a much slower rate. C) There would be more cellular damage from harmful products of the light reactions of photosynthesis. D) Less oxygen would be produced by photosynthesis.

MORE CELLULAR DAMAGE from harmful products of the light reactions

The genetic code is REDUNDANT. What is meant by this statement? A) A single codon can specify the addition of more than one amino acid. B) The genetic code is different for different domains of organisms. C) The genetic code is universal (the same for all organisms). D) More than one codon can specify the addition of the same amino acid.

MORE THAN ONE codon can SPECIFY the addition of the same amino acid

A newly discovered unicellular organism isolated from ACIDIC MINE DRAINAGE is found to contain a cell wall, a plasma membrane, two flagella, and peroxisomes. Based just on this information, the organism is most likely ________. A) a nonmotile prokaryote B) a motile bacterium C) a motile archaea D) a nonmotile eukaryote E) a motile eukaryote

MOTILE EUKARYOTE

Researchers investigating the mechanism of vesicular transport assembled a cell-free system that included microtubule tracks, vesicles, and ATP. However, they observed no movement of transport of vesicles in this system. What were they missing? A) an axon B) contractile microfilaments C) intermediate filaments D) motor proteins

MOTOR PROTEINS

Which of the following molecules triggers the cell's passage past the G2 checkpoint into mitosis? A) PDGF B) MPF C) cyclin D) Cdk Answer:

MPF

Why are males more often affected by sex-linked traits than females? A) Male hormones such as testosterone often alter the effects of mutations on the X chromosome. B) Female hormones such as estrogen often compensate for the effects of mutations on the X chromosome. C) X chromosomes in males generally have more mutations than X chromosomes in females. D) Males are hemizygous for the X chromosome.

Males are hemizygous for the X chromosome.

Agrobacterium infects plants and causes them to form tumors. You are asked to determine how long a plant must be exposed to these bacteria to become infected. Which of the following experiments will provide the best data to address that question? A) Determine the survival rate of Agrobacterium when exposed to different concentrations of an antibiotic. B) Measure the number of tumors formed on a plant when exposed to various concentrations of Agrobacterium. C) Measure the concentration of Agrobacterium in different soil environments where the plants grow. D) Measure the number of tumors formed on plants, which are exposed to Agrobacterium for different lengths of time.

Measure the number of tumors formed on plants, which are exposed to Argobacterium for different lengths of time

Which of the following statements describes a major difference between meiosis II and mitosis in a diploid animal? A) Homologous chromosomes align on the metaphase plate in meiosis II. B) Sister chromatids separate in mitosis, and homologous chromosomes separate in meiosis II. C) Meiosis II occurs in a haploid cell, while mitosis occurs in diploid cells. D) Crossing over of chromosomes takes place in meiosis II.

Meiosis II occurs in a haploid cell, while mitosis occurs in diploid cells.

Which of the following statements correctly describes the meaning of the chromosome theory of inheritance as expressed in the early 20th century? A) Individuals inherit particular chromosomes attached to genes. B) Mendelian genes are at specific loci on the chromosome and, in turn, segregate during meiosis. C) No more than a single pair of chromosomes can be found in a healthy normal cell. D) Natural selection acts on certain chromosome combinations rather than on genes.

Mendelian genes are at specific loci on the chromosome and, in turn, segregate during meiosis.

Who performed classic experiments that supported the SEMICONSERVATIVE model of DNA replication? A) Watson and Crick B) Meselson and Stahl C) Hershey and Chase D) Franklin and Wilkins

Meselson and Stahl

Which of the following statements is true of metabolism in its entirety in all organisms? A) Metabolism depends on a constant supply of energy from food. B) Metabolism uses all of an organism's resources. C) Metabolism consists of all the energy transformation reactions in an organism. D) Metabolism manages the increase of entropy in an organism.

Metabolism consists of all the energy transformation reactions in an organism.

Genomic imprinting is generally due to the addition of methyl (-CH3) groups to C nucleotides and chemical histone changes to silence a given gene. If this depends on the sex of the parent who transmits the gene, which of the following statements must be true? A) Genes required for early development stages must not be imprinted. B) Methylation of this kind must occur more in males than in females. C) Methylation must be reversible in ovarian and testicular cells. D) The imprints are transmitted only to gamete-producing cells.

Methylation must be reversible in ovarian and testicular cells.

The atomic number of chlorine is 17. The atomic number of magnesium is 12. What is the formula for magnesium chloride? A) MgCl B) MgCl2 C) Mg2Cl D) MgCl3

MgCl2

In his transformation experiments, what phenomenon did Griffith observe? A) Mixing a heat-killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living cells into the pathogenic form. B) Mixing a heat-killed nonpathogenic strain of bacteria with a living pathogenic strain makes the pathogenic strain nonpathogenic. C) Infecting mice with nonpathogenic strains of bacteria makes them resistant to pathogenic strains. D) Mice infected with a pathogenic strain of bacteria can spread the infection to other mice.

Mixing a heat-killed PATHOGENIC strain of bacteria with a living nonpathogenic strain can CONVERT some of the living cells into pathogenic forms

Molybdenum has an atomic number of 42. Several common isotopes exist, with mass numbers from 92-100. Which of the following can be true? A) Molybdenum atoms can have between 50 and 58 neutrons. B) Molybdenum atoms can have between 50 and 58 protons. C) Molybdenum atoms can have between 50 and 58 electrons. D) Isotopes of molybdenum have different numbers of electrons.

Molybdenum atoms can have between 50 and 58 NEUTRONS

Which of the following statements is generally true of aneuploidies in newborns? A) A monosomy is more frequent than a trisomy. B) Monosomy X is the only viable monosomy known to occur in humans. C) Human aneuploidy usually conveys an adaptive advantage in humans. D) An aneuploidy resulting in the deletion of a chromosome segment is less serious than a duplication.

Monosomy X is the only viable monosomy known to occur in humans.

In the figure, why does the reaction rate plateau at higher reactant concentrations? A) Feedback inhibition by product occurs at high reactant concentrations. B) Most enzyme molecules are occupied by substrate at high reactant concentrations. C) The reaction nears equilibrium at high reactant concentrations. D) The rate of the reverse reaction increases at high reactant concentrations.

Most enzyme molecules are occupied by substrate at high reactant concentrations.

The free energy for the oxidation of glucose to CO2 and water is -686 kcal/mol, and the free energy for the reduction of NAD+ to NADH is +53 kcal/mol. Why are only two molecules of NADH formed during glycolysis when it appears that as many as a dozen could be formed? A) Most of the free energy available from the oxidation of glucose is used in the production of ATP in glycolysis. B) Glycolysis is a very inefficient reaction, with much of the energy of glucose released as heat. C) Most of the free energy available from the oxidation of glucose remains in pyruvate, one of the products of glycolysis. D) There is no CO2 or water produced as products of glycolysis.

Most of the free energy available from the oxidation of glucose remains in pyruvate, one of the products of glycolysis.

Which of the following statements about the cytoskeleton is true? A) The cytoskeleton of eukaryotes is a static structure most resembling scaffolding used at construction sites. B) Although microtubules are common within a cell, actin filaments are rarely found outside of the nucleus. C) Movement of cilia and flagella is the result of motor proteins causing microtubules to move relative to each other. D) Chemicals that block the assembly of the cytoskeleton would have little effect on a cell's response to external stimuli.

Movement of cilia and flagella is the result of motor proteins causing microtubules to move relative to each other.

Following glycolysis and the citric acid cycle, but before the electron transport chain and oxidative phosphorylation, the carbon skeleton of glucose has been broken down to CO2 with some net gain of ATP. Most of the energy from the original glucose molecule at that point in the process, however, is stored in the form of which of the following molecules? A) acetyl-CoA B) NAD+ C) pyruvate D) NADH

NADH

Which electron carrier(s) function in the citric acid cycle? A) NAD+ only B) NADH and FADH2 C) the electron transport chain D) ADP and ATP

NADH and FADH2

Which molecule is the FINAL ELECTRON ACCEPTOR for electrons from photosystem I? A) oxygen B) chlorophyll in photosystem II C) carbon dioxide D) NADP+

NADP+

The REDUCING power for Calvin cycle reactions is provided by which of the following molecules? A) ATP B) NADH C) NADP+ D) NADPH

NADPH

CARBON DIOXIDE IS SPLIT to form oxygen gas and carbon compounds in which of the following metabolic pathways? A) only photosynthesis B) only respiration C) photosynthesis and respiration D) neither photosynthesis nor respiration

NEITHER NOR

A solution contains 0.0000001 (10-7) moles of hydrogen ions [H+] per liter. Which of the following best describes this solution? A) acidic: H+ acceptor B) basic: H+ acceptor C) acidic: H+ donor D) neutral

NEUTRAL

In E. coli, there is a mutation in a gene called dnaB that alters the helicase that normally acts at the origin of replication. Which of the following events would you expect to occur as a result of this mutation? A) Additional proofreading will occur. B) No replication fork will be formed. C) Replication will occur via RNA polymerase alone. D) Replication will require a DNA template from another source.

NO replication FORK

Hydrophobic substances such as vegetable oil are ________. A) nonpolar substances that repel water molecules B) nonpolar substances that have an attraction for water molecules C) polar substances that repel water molecules D) polar substances that have an affinity for water

NONPOLAR substances that REPEL water molecules

G1 is associated with which of the following cellular events? A) normal growth and cell function B) DNA replication C) the beginning of mitosis D) break down of the nuclear membrane

NORMAL growth and cell function

Sulfur is in the same column of the periodic table as oxygen, but has electronegativity similar to carbon. Compared to water molecules, molecules of H2S will ________. A) have greater cohesion to other molecules of H2S B) have a greater tendency to form hydrogen bonds with each other C) have a higher capacity to absorb heat for the same change in temperature D) not form hydrogen bonds with each other

NOT form hydrogen bonds with each other

The spontaneous loss of amino groups from adenine in DNA results in hypoxanthine, an uncommon base, opposite thymine. What combination of proteins could REPAIR SUCH DAMAGE? A) nuclease, DNA polymerase, DNA ligase B) telomerase, primase, DNA polymerase C) telomerase, helicase, single-strand binding protein D) DNA ligase, replication fork proteins, adenylyl cyclase

NUCLEASE, DNA polymerase, DNA ligase

In bacteria, DNA will be found in ________. A) a membrane-enclosed nucleus B) mitochondria C) the nucleoid D) ribosomes

NUCLEOID

Which of the following lists represents the order of increasingly higher levels of ORGANIZATION OF CHROMATIN? A) nucleosome, 30-nm chromatin fiber, looped domain B) looped domain, 30-nm chromatin fiber, nucleosome C) nucleosome, looped domain, 30-nm chromatin fiber D) 30-nm chromatin fiber, nucleosome, looped domain

NUCLEOSOME, 30 nm, chromatin fiber, looped domain

Which of the following is considered to be a strong base (alkali)? A) HCl → H+ + Cl- B) NH3 + H+ ⇔ NH4+ C) H2CO3 ⇔ HCO3- + H+ D) NaOH → Na+ + OH-

NaOH > Na+ + OH-

Which of the following statements is a correct explanation for the observation that all offspring exhibit a phenotype for a particular trait that appears to be a blend of the two parental varieties? A) Neither of the parental genes is dominant over the other. B) The genes for the trait are dominant in both of the parents. C) The genes are linked and do not separate during meiosis. D) The genes for the trait are recessive in both of the parents.

Neither of the parental genes is dominant over the other.

What is an adaptive advantage of recombination between linked genes? A) Recombination is required for independent assortment. B) Recombination must occur or genes will not assort independently. C) New allele combinations are acted upon by natural selection. D) The forces on the cell during meiosis II result in recombination.

New allele combinations are acted upon by natural selection.

Which pair of elements would likely have similar valency and thus similar chemical behavior? A) nitrogen and phosphorus B) carbon and nitrogen C) sodium and chlorine D) hydrogen and helium

Nitrogen and phosphorus

If an enzyme is added to a solution where its substrate and product are in equilibrium, what will occur? A) Additional substrate will be formed. B) The reaction will change from endergonic to exergonic. C) The free energy of the system will change. D) Nothing; the reaction will stay at equilibrium.

Nothing; the reaction will stay at equilibrium.

Which of the following would likely DIFFUSE through the lipid bilayer of a plasma membrane most RAPIDLY? A) sucrose B) an amino acid C) O2 D) Na+

E. coli cells grown on 15N medium are transferred to 14N medium and allowed to grow for two more generations (two rounds of DNA replication). DNA extracted from these cells is centrifuged. What DENSITY DISTRIBUTION of DNA would you expect in this experiment? A) one high-density and one low-density band B) one intermediate-density band C) one high-density and one intermediate-density band D) one low-density and one intermediate-density band

ONE LOW-density and one intermediate density band

SEMICONSERVATIVE replication involves a template. What is the template? A) single-stranded binding proteins B) DNA polymerase C) one strand of the DNA molecule D) an RNA molecule

ONE STRAND of the DNA molecule

CAM plants keep stomata closed in the daytime, thus reducing loss of water. They can do this because they ________. A) fix CO2 into organic acids during the night B) fix CO2 into sugars in the bundle-sheath cells C) fix CO2 into pyruvate in the mesophyll cells D) use photosystem I and photosystem II at night

ORGANIC ACIDS DURING NIGHT

STANLEY MILLER'S 1953 experiments supported the hypothesis that ________. A) life on Earth arose from simple inorganic molecules B) organic molecules can be synthesized abiotically under conditions that may have existed on early Earth C) life on Earth arose from simple organic molecules, with energy from lightning and volcanoes D) the conditions on early Earth were conducive to the origin of life

ORGANIC molecules can be synthesized ABIOTICALLY under conditions that may have existed on early Earth

In autumn, CHLOROPHYLL IS DEGRADED in the leaves of deciduous trees. Why do the leaves change color to shades of yellow, orange, or red? A) Sugars from sap fill the leaves prior to winter. B) Degraded chlorophyll changes into many other colors. C) In the absence of photosynthesis, the leaves produce energy exclusively by aerobic cellular respiration. D) Other pigments such as carotenoids are still present in the leaves.

OTHER PIGMENTS such as CAROTENOIDS are still present in the leaves

Which of the following statements describes a primary function of both alcohol fermentation and lactic acid fermentation? A) reduction of NAD+ to NADH B) reduction of FAD to FADH2 C) oxidation of NADH to NAD+ D) hydrolysis of ATP to ADP + i

OXIDATION

The mechanism of photophosphorylation is most similar to which of the following processes? A) substrate-level phosphorylation in glycolysis B) oxidative phosphorylation in cellular respiration C) the Calvin cycle D) reduction of NADP+

OXIDATIVE

In mechanism, photophosphorylation is most similar to A) substrate-level phosphorylation in glycolysis. B) oxidative phosphorylation in cellular respiration. C) carbon fixation. D) reduction of NADP+.

OXIDATIVE PHOSPHORYLATION

What happens to a GLUCOSE molecule when it LOSES a HYDROGEN atom as the result of an oxidation-reduction reaction? A) The glucose molecule is hydrolyzed. B) The glucose molecule is an oxidizing agent. C) The glucose molecule is oxidized. D) The glucose molecule is reduced.

OXIDIZED

MILLER's classic experiment demonstrated that a discharge of SPARKS through a mixture of gases could result in the formation of a large variety of organic compounds. Miller did not use ________ as one of the gases in his experiment. A) methane B) oxygen C) water D) ammonia

OXYGEN

Following a scientific method, which of the following is the correct order of steps? A) Observation → Analysis → Hypothesis → Conclusion → Communicate results → Experiment B) Observation → Hypothesis → Experiment → Communicate results → Analysis → Conclusion C) Experiment → Hypothesis → Observation → Analysis → Conclusion → Communicate results D) Observation → Hypothesis → Experiment → Analysis → Conclusion → Communicate results

Observation, hypothesis, experiment, analysis, conclusion, communicate results

Why did all of the F1 offspring of Mendel's classic pea cross always look like one of the two parental varieties? A) No genes interacted to produce the parental phenotype. B) Each allele affected phenotypic expression. C) The traits blended together during fertilization. D) One allele was dominant.

One allele was dominant.

A couple has a child with Down syndrome. The mother is 39 years old at the time of delivery. Which of the following is the most probable cause of the child's condition? A) The woman inherited this tendency from her parents. B) The mother had a chromosomal duplication. C) One member of the couple underwent nondisjunction in somatic cell production. D) One of the gametes in the mother most likely underwent nondisjunction during meiosis.

One of the gametes in the mother most likely underwent nondisjunction during meiosis.

One of two major forms of a human condition called neurofibromatosis (NF1) is inherited as a dominant gene, although it may range from mildly to very severely expressed. Which of the following is the best explanation for why a young, affected child is the first in her family to be diagnosed? A) The mother carries the gene but does not express it. B) One of the parents has a mild expression of the gene. C) The condition skipped a generation in the family. D) The child has one more chromosome than either of the parents.

One of the parents has a mild expression of the gene.

Duchenne muscular dystrophy is a serious condition caused by a recessive allele of a gene on the human X chromosome. The patients have muscles that weaken over time because they have absent or decreased dystrophin, a muscle protein. They rarely live past their 20s. How likely is it for a woman to have this condition? A) Women can never have this condition. B) One-fourth of the daughters of an affected man would have this condition. C) One-half of the daughters of an affected father and a carrier mother could have this condition. D) Only if a woman is XXX could she have this condition.

One-half of the daughters of an affected father and a carrier mother could have this condition.

If cell X enters meiosis, and nondisjunction of one chromosome occurs in one of its daughter cells during meiosis II, how will this affect the gametes at the completion of meiosis? A) All the gametes descended from cell X will be diploid. B) Half of the gametes descended from cell X will be n + 1, and half will be n - 1. C) One-quarter of the gametes descended from cell X will be n + 1, one-quarter will be n - 1, and half will be n. D) Two of the four gametes descended from cell X will be haploid, and two will be diploid.

One-quarter of the gametes descended from cell X will be n + 1, one-quarter will be n - 1, and half will be n.

A phenotypically normal prospective couple seeks genetic counseling because the man knows that he has a translocation of a portion of his chromosome 4, which has been exchanged with a portion of his chromosome 12. Although his translocation is balanced, he and his wife want to know the probability that his sperm will be abnormal. What is your prognosis regarding his sperm? A) One-quarter will carry the two normal chromosomes, 4 and 12, one-quarter will have only the two translocation chromosomes and no normal chromosomes 4 and 12, and half will have one normal and one translocated chromosome. B) All will carry the same translocation as the father. C) None will carry the translocation. D) Half will be normal, and the rest will have the father's translocation.

One-quarter will carry the two normal chromosomes, 4 and 12, one-quarter will have only the two translocation chromosomes and no normal chromosomes 4 and 12, and half will have one normal and one translocated chromosome.

If pyruvate oxidation is blocked, what will happen to the levels of oxaloacetate and citric acid in the citric acid cycle shown in the accompanying figure? A) Oxaloacetate will decrease and citric acid will accumulate. B) Oxaloacetate will accumulate and citric acid will decrease. C) Both oxaloacetate and citric acid will decrease. D) Both oxaloacetate and citric acid will accumulate.

Oxaloacetate will accumulate and citric acid will decrease.

Which of the following is a type of LOCAL SIGNALING in which a cell secretes a signal molecule that affects NEIGHBORING CELLS? A) hormonal signaling B) autocrine signaling C) paracrine signaling D) synaptic signaling

PARACRINE

Which of the following statements about DIFFUSION is true? A) It is very rapid over long distances. B) It requires an expenditure of energy by the cell. C) It is an active process in which molecules move from a region of lower concentration to a region of higher concentration. D) It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration.

PASSIVE PROCESS in which molecules moves from HIGH to LOW concentration

Which of the following processes INCLUDES ALL of the others? A) osmosis B) facilitated diffusion C) passive transport D) transport of an ion down its electrochemical gradient

PASSIVE TRANSPORT

Which of the following molecules is released by platelets in the vicinity of an injury? A) PDGF B) MPF C) cyclin D) Cdk

PDGF

Which of the following types of molecules are hydrophilic and therefore EXCLUDED from the HYDROPHOBIC portion of the phospholipid bilayer? A) transmembrane proteins B) integral membrane proteins C) peripheral membrane proteins D) cholesterol

PERIPHERAL MEMBRANE proteins

A heat-killed, phosphorescent (light-emitting) strain of bacteria is mixed with a living, non- phosphorescent strain. Further observations of the mixture show that some of the living cells are now phosphorescent. Which of the following observations would provide the best evidence that the ability to phosphoresce is a heritable trait? A) evidence that DNA was passed from the heat-killed strain to the living strain B) evidence that protein passed from the heat-killed strain to the living strain C) especially bright phosphorescence in the living strain D) phosphorescence in descendants of the living cells

PHOSPHORESCENCE in descendants of the living cell

In photosynthetic cells, synthesis of ATP by CHEMISIOSIS occurs during ________. A) photosynthesis only B) respiration only C) photosynthesis and respiration D) photosynthesis, respiration, and fermentation

PHOTOSYNTHESIS and RESPIRATION

In which of the following organisms did the process of PHOTOSYNTHESIS most likely ORIGINATE? A) in plants B) in prokaryotes C) in fungi D) three separate times during evolution

PROKARYOTES

Which of the following DIPEPTIDES will form from this mRNA? A) cysteine-alanine B) proline-threonine C) glycine-cysteine D) alanine-alanine

PROLINE- threonine

Examination of a cell by transmission electron microscopy reveals a high density of ribosomes in the cytoplasm. This observation suggests that this cell is actively producing large amounts of which of the following molecules? A) polysaccharides B) proteins C) lipids D) nucleic acids

PROTEINS

What would be the consequence of a mutation in a bacterial cell that produces DEFECTIVE AMINOACYLl-tRNA SYNTHETASE that attaches a lysine instead of the normal phenylalanine to tRNAs with the anticodon AAA? A) None of the proteins in the cell will contain phenylalanine. B) Proteins in the cell will include lysine instead of phenylalanine at amino acid positions specified by the codon UUU. C) The cell will compensate for the defect by attaching phenylalanine to tRNAs with lysine- specifying anticodons. D) The ribosome will skip a codon every time a UUU is encountered.

PROTEINS in the cell will include LYSINE instead of phenylalanine at the amino acid positions specified by the codon UUU

What is the oxidizing agent in the following reaction? Pyruvate + NADH + H+ → Lactate + NAD+ A) NADH B) NAD+ C) lactate D) pyruvate

PYRUVATE

When a plant cell, such as one from a tulip leaf, is submerged in a hypertonic solution, what is likely to occur? A) The cell will burst. B) Plasmolysis will shrink the interior of the cell. C) The cell will become flaccid. D) The cell will become turgid.

Plasmolysis will shrink

Which of the following statements is true of signal molecules? A) When signal molecules first bind to receptor tyrosine kinases, the receptors phosphorylate a number of nearby molecules. B) In response to some G protein-mediated signals, a special type of lipid molecule associated with the plasma membrane is cleaved to form IP3 and calcium. C) In most cases, signal molecules interact with the cell at the plasma membrane, enter the cell, and eventually enter the nucleus. D) Protein kinase A activation is one possible result of signal molecules binding to G protein- coupled receptors.

Protein kinase A activation is one possible result of signal molecules binding to G protein- coupled receptors.

Which of the following statements correctly describes some aspect of protein secretion from prokaryotic cells? A) Prokaryotes cannot secrete proteins because they lack an endomembrane system. B) Proteins secreted by prokaryotes are likely synthesized on ribosomes bound to the cytoplasmic surface of the plasma membrane. C) The mechanism of protein secretion in prokaryotes is probably the same as that in eukaryotes. D) Prokaryotes cannot secrete proteins because they lack rough endoplasmic reticulum.

Proteins secreted by prokaryotes are likely synthesized on ribosomes bound to the cytoplasmic surface of the plasma membrane

Proton pumps are used in various ways by members of every domain of organisms: Bacteria, Archaea, and Eukarya. What does this fact most probably mean? A) Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life. B) The high concentration of protons in the ancient atmosphere must have necessitated a pump mechanism. C) Cells of each domain evolved proton pumps independently when oceans became more acidic. D) Proton pumps are necessary to all cell membranes.

Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life.

Which of the following frequently IMPOSES A LIMIT ON CELL SIZE? A) the absence of a nucleus B) the number of mitochondria in the cytoplasm C) ratios of surface area to volume D) the volume of the endomembrane system

RATIOS of SURFACE AREA

Which of the following processes is DIRECTLY ASSOCIATED with PHOTOSYSTEM I? A) receiving electrons from the thylakoid membrane electron transport chain B) generation of molecular oxygen C) extraction of hydrogen electrons from the splitting of water D) passing electrons to NADP+

RECEIVING electrons from the THYLAKOID membrane electron transport chain

When a molecule of NAD+ (nicotinamide adenine dinucleotide) GAINS HYDROGEN atom (not a proton), the molecule becomes ________. A) dehydrogenated B) oxidized C) reduced D) redoxed

REDUCED

Which of the following statements about NAD+ is true? A) NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid cycle. B) NAD+ has more chemical energy than NADH. C) NAD+ can donate electrons for use in oxidative phosphorylation. D) In the absence of NAD+, glycolysis can still function.

REDUCED to NADH during GLYCOLYSIS

Which of the following processes occurs during the Calvin cycle? A) reduction of NADPH B) release of oxygen C) regeneration of the CO2 acceptor D) production of ATP

REGENERATION of the CO2 ACCEPTOR

Which of the following doesNOT occur during the Calvin cycle? A) carbon fixation B) oxidation of NADPH C) release of oxygen D) regeneration of the CO2 acceptor

RELEASE OF OXYGEN

What is the function of the enzyme topoisomerase in DNA replication? A) relieving strain in the DNA ahead of the replication fork caused by the untwisting of the double helix B) elongating new DNA at a replication fork by adding nucleotides to the existing chain C) reattaching the hydrogen bonds between the base pairs in the double helix D) building RNA primers using the parental DNA strand as a template

RELIEVING STRAIN in the DNA ahead of the replication FORK caused by the untwisting of the double helix

Which of the following processes is most directly DRIVEN BY LIGHT energy? A) creation of a pH gradient by pumping protons across the thylakoid membrane B) carbon fixation in the stroma C) reduction of NADP+ molecules D) removal of electrons from chlorophyll molecules

REMOVAL of electrons from CHLOROPHYLL molecules

Which of the following events occurs during INTERPHASE of the cell cycle? A) condensation of the chromosomes B) separation of the spindle poles C) spindle formation D) replication of the DNA

REPLICATION for DNA

In the fractionation of homogenized cells using differential CENTRIFUGATION, which of the following will require the greatest speed to form PELLETS at the bottom of the tube? A) nuclei B) mitochondria C) chloroplasts D) ribosomes

RIBOSOMES

Which one of the following statements about RNA PROCESSING is correct? A) Exons are cut out before mRNA leaves the nucleus. B) Ribozymes may function in RNA splicing. C) RNA splicing can be catalyzed by tRNA. D) A primary transcript is often much shorter than the final RNA molecule that leaves the

RIBOZYMES may function in RNA SPLICING

If 14C-labeled uracil is added to the growth medium of cells, what macromolecules will be labeled? A) DNA B) RNA C) both DNA and RNA D) polypeptides

RNA

Which of the following processes occurs DURING TRANSCRIPTION? A) DNA is replicated B) RNA is synthesized C) proteins are synthesized D) mRNA attaches to ribosomes

RNA IS SYNTHESIZED

In eukaryotes, there are several different types of RNA polymerase. Which type is involved in transcription of mRNA for a GLOBIN PROTEIN? A) RNA polymerase I B) RNA polymerase II C) RNA polymerase III D) primase

RNA POLYMERASE II

Which of the following statements best describes the TERMINATION OF TRANSCRIPTION IN PROKARYOTES? A) RNA polymerase transcribes through the polyadenylation signal, causing proteins to associate with the transcript and cut it free from the polymerase. B) RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript. C) Once transcription has initiated, RNA polymerase transcribes until it reaches the end of the chromosome. D) RNA polymerase transcribes through a stop codon, causing the polymerase to stop advancing through the gene and release the mRNA.

RNA polymerase transcribes through the TERMINATOR sequence causing the polymerase to separate from the DNA and release transcript

Which of the following statements correctly describes a RIBOSOME? A) It is a catalyst that uses RNA as a substrate. B) It is an RNA with catalytic activity. C) It is an enzyme that catalyzes the association between the large and small ribosomal subunits. D) It is an enzyme that synthesizes RNA as part of the transcription process.

RNA with CATALYTIC ACTIVITY

You have a cube of modeling clay in your hands. Which of the following changes to the shape of this cube of clay will decrease its surface area relative to its volume? A) Pinch the edges of the cube into small folds. B) Flatten the cube into a pancake shape. C) Round the clay up into a sphere. D) Stretch the cube into a long, shoebox shape.

ROUND CLAY TO SPHERE

How is photosynthesis similar in C4 plants and CAM plants? A) In both cases, only photosystem I is used. B) Both types of plants make sugar without the Calvin cycle. C) In both cases, rubisco is not used to fix carbon initially. D) Both types of plants make most of their sugar in the dark.

RUBISCO NOT USED

Why is the ΔG of ATP hydrolysis in the cell about twice as great as the ΔG of ATP hydrolysis in a test tube under standard conditions? A) A cell is an open system, whereas a test tube is a closed system. B) ATP hydrolysis in a test tube releases more heat than ATP hydrolysis associated with cellular metabolism. C) Reactant and product concentrations in the test tube are different from those in the cell. D) ATP hydrolysis in cells is catalyzed by enzymes, whereas the reaction in a test tube occurs spontaneously.

Reactant and product concentrations in the test tube are different from those in the cell.

Phenylketonuria (PKU) is a recessive human disorder in which an individual cannot appropriately metabolize the amino acid phenylalanine. This amino acid is not naturally produced by humans. Which of the following treatments would be most effective for people with PKU? A) Feed them the substrate that can be metabolized into phenylalanine. B) Regulate the diet of the affected persons to severely limit the uptake of phenylalanine. C) Feed the patients the missing enzymes in a regular cycle, such as twice per week. D) Feed the patients an excess of the missing product.

Regulate the diet of the affected persons to severely limit the uptake of phenylalanine.

What is the function of the nuclear pore complex found in eukaryotes? A) It regulates the movement of proteins and RNAs into and out of the nucleus. B) It synthesizes the proteins required to copy DNA and make mRNA. C) It synthesizes secreted proteins. D) It assembles ribosomes from raw materials that are synthesized in the nucleus.

Regulates the movement of proteins and RNAs into and out of the nucleus.

Why is a scientific topic best discussed by people of varying points of view, from different subdisciplines, and representing diverse cultures? A) Robust and critical discussion between diverse groups improves scientific thinking. B) Scientists can coordinate with others to conduct experiments in similar ways. C) This is a way of ensuring that everyone gets the same results. D) People need to exchange their ideas with other disciplines and cultures because everyone has a right to an opinion in science.

Robust and critical discussion between diverse groups improves scientific thinking

In the initial step in carbon fixation, a molecule of CO2 is attached to RuBP to produce a six- carbon molecule, which is immediately split to produce two molecules of 3-phosphoglycerate. After phosphorylation and reduction produces glyceraldehyde 3-phosphate (G3P), what more needs to occur to complete the Calvin cycle? A) addition of a pair of electrons from NADPH B) regeneration of ATP from ADP C) regeneration of RuBP D) regeneration of NADP+

RuBP

In which of the following environments would there be the greatest need for osmoregulation? A) an animal connective tissue cell bathed in isotonic body fluid B) a salmon moving from a river into an ocean C) a red blood cell surrounded by plasma D) a plant being grown hydroponically in a watery mixture of designated nutrients

SALMON

How does the primary transcript in the nucleus of a PROKARYOTIC cell compare to the functional mRNA? A) the primary transcript is larger than the mRNA B) the primary transcript is smaller than the mRNA C) the primary transcript and the mRNA both contain introns D) the primary transcript is the same size as the mRNA

SAME SIZE

Which of the following would be most appropriate method to observe the three-dimensional structure and organization of MICROVILI on an intestinal cell? A) a hand lens (magnifying glass) B) standard light microscopy C) scanning electron microscopy D) transmission electron microscopy

SCANNING ELECTRON

The MITOTIC SPINDLE plays a critical role in which of the following processes? A) splitting of the cell (cytokinesis) following mitosis B) triggering the compaction and condensation of chromosomes C) dissolving the nuclear membrane D) separation of sister chromatids

SEPARATION of SISTER chromatids

It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information. Which of the following characteristics of DNA is responsible for this? A) sequence of bases B) phosphate-sugar backbones C) complementary pairing of bases D) side groups of nitrogenous bases

SEQUENCE of bases

In eukaryotic cells, TRANSCRIPTION CANNOT BEING until A) the two DNA strands have completely separated and exposed the promoter. B) several transcription factors have bound to the promoter. C) the 5 caps are removed from the mRNA. D) the DNA introns are removed from the template.

SEVERAL transcription FACTORS have bound to the promoter

TRANSCRIPTION IN EUKARYOTES requires which of the following molecules in addition to RNA polymerase? A) anticodons B) ribosomes and tRNA C) several transcription factors D) aminoacyl-tRNA synthetase

SEVERAL transcription factors

Movement of the chromosomes during ANAPHASE would be most affected by a DRUG THAT PREVENTS which of the following events in mitosis and cell division? A) nuclear envelope breakdown B) elongation of microtubules C) shortening of microtubules D) formation of a cleavage furrow

SHORTENING of microtubules

A compound contains hydroxyl groups as its PREDOMINANT FUNCTIONAL GROUP. Therefore, this compound ________. A) lacks an asymmetric carbon and is probably a fat or lipid B) should dissolve in water C) should dissolve in a nonpolar solvent D) will not form hydrogen bonds with water

SHOULD dissolve in WATER

When a neuron responds to a particular neurotransmitter by OPENING GATED ion channels, the neurotransmitter is serving as which part of the SIGNAL pathway? A) relay molecule B) transducer C) signal molecule D) response molecule

SIGNAL MOLECULE

A research team is working on the design of a new DRUG FOR THE TREATMENT OF LUNG CANCER. To be most effective, this drug must specifically enter the cytoplasm of lung cells while not entering the cells of other tissues. Which of the following characteristics would likely enhance the specificity of this drug? A) the relative hydrophobicity of the drug molecule B) phospholipid composition of lung cell plasma membranes C) specificity of the drug molecule for binding to the extracellular matrix of lung cells D) similarity of the drug molecule to other molecules normally transported lung cells

SIMILARITY of drug molecule to other molecules NORMALLY TRANSPORTED LUNG CELLS

Which of the following types of molecules help to hold the DNA strands apart while they are being replicated? A) primase B) ligase C) DNA polymerase D) single-strand DNA binding proteins

SINGLE STRAND DNA binding proteins

Which of the following are LEAST LIKELY TO DIFFUSE through the phospholipid bilayer of a cell membrane? A) large hydrophobic molecules B) small hydrophobic molecules C) carbon dioxide D) small ions

SMALL IONS

What kinds of molecules PASS THROUGH CELL MEMBRANE MOST EASILY? A) large and hydrophobic B) small and hydrophobic C) large polar D) small and ionic

SMALL and HYDROPHOBIC

In his work with pneumonia-causing bacteria and mice, GRIFFITH found that A) the protein coat from pathogenic cells was able to transform nonpathogenic cells. B) heat-killed pathogenic cells caused pneumonia. C) some substance from pathogenic cells was transferred to nonpathogenic cells, making them pathogenic. D) the polysaccharide coat of bacteria caused pneumonia.

SOME SUBSTANCE from pathogenic cells was transferred to nonpathogenic cells making them pathogenic

The OXYGEN RELEASED by photosynthesis is PRODUCED by which of the following processes? A) splitting water molecules B) chemiosmosis C) the electron transfer system of photosystem I D) the electron transfer system of photosystem II

SPLITTING WATER MOLECULES

Why does ice float in liquid water? A) The high surface tension of liquid water keeps the ice on top. B) The ionic bonds between the molecules in ice prevent the ice from sinking. C) Stable hydrogen bonds keep water molecules of ice farther apart than water molecules of liquid water. D) The crystalline lattice of ice causes it to be denser than liquid water.

STABLE hydrogen bonds keep water molecules of ice farther apart than water molecules of liquid water

Which of the following would be the most appropriate method to observe the MOVEMENTS OF CONDENSED CHROMOSOMES during cell division? A) a hand lens (magnifying glass) B) standard light microscopy C) scanning electron microscopy D) transmission electron microscopy

STANDARD LIGHT microscopy

Which of the following processes occurs when TERMINATION OF TRANSLATION takes place? A) The end of the mRNA molecule is reached. B) A stop codon is reached. C) The 5′ cap is reached. D) The poly-A tail is reached.

STOP CODON reached

Where in a plant cell does the Calvin cycle take place? A) stroma of the chloroplast B) thylakoid membrane C) interior of the thylakoid (thylakoid space) D) outer membrane of the chloroplast

STROMA of CHLOROPLASTS

In MITOCHONDRIA, an electron transport chain PUMPS PROTONS from the matrix into the intermembrane space, whereas in chloroplasts, an electron transport chain pumps protons from the ________. A) matrix to the stroma B) stroma to the thylakoid space C) thylakoid space to the matrix D) thylakoid space to the stroma

STROMA to the THYLAKOID

Which of the following is a major difference between RNA and DNA? A) type of sugar B) type of phosphate C) type of purines D) type of glycosidic bond

SUGAR

Which functional group is NOT PRESENT in this molecule? A) carboxyl B) sulfhydryl C) hydroxyl D) amino

SULFHYDRYL

Which of the following TYPES OF SIGNALING is represented in the figure? A) autocrine B) paracrine C) hormonal D) synaptic

SYNAPTIC

Which of the following processes would be most directly affected if a THYLAKOID MEMBRANE IS PUNCTURED so that the interior of the thylakoid is no longer separated from the stroma? A) splitting of water B) flow of electrons from photosystem II to photosystem I C) synthesis of ATP D) reduction of NADP+

SYNTHESIS of ATP

Genetic variation leads to genetic diversity in populations and is the raw material for evolution. Biological systems have multiple processes, such as reproduction, that affect genetic variation. They are evolutionarily conserved and shared by various organisms. Which of the following statements best represents the connection between reproduction and evolution? A) Plants that use sexual reproduction are rare since this type of reproduction in plants does not contribute to genetic diversity. B) In order to increase genetic diversity for evolution in sexually reproducing organisms, mutations must occur in the zygote after fertilization. C) Since prokaryotic organisms reproduce asexually, there is no mechanism for them to add genetic diversity for evolution. D) Sexual reproduction increases genetic variation because random mutations can be shuffled between organisms.

Sexual reproduction increases genetic variation because random mutations can be shuffled between organisms.

How does natural selection apply to sexual reproduction as opposed to asexual reproduction? A) Sexual reproduction results in many new gene combinations, some of which will lead to differential reproduction. B) Sexual reproduction results in the greatest number of new mutations. C) Sexual reproduction allows the greatest number of offspring to be produced. D) Sexual reproduction utilizes far less energy than asexual reproduction.

Sexual reproduction results in many new gene combinations, some of which will lead to differential reproduction.

In presenting data that result from an experiment, a group of students show that most of their measurements fall on a straight diagonal line on their graph. However, two of their data points are "outliers" and fall far to one side of the expected relationship. What should they do? A) Do not show these points because clearly something went wrong in the experiment. B) Average several trials, rule out the improbable results, and do not show them in the final work. C) Show all results obtained and then try to explore the reason(s) for these outliers. D) Change the details of the experiment until they can obtain the expected results.

Show all results obtained and try to explore the reason for the ouliers

At the beginning of the U-tube experiment illustrated above, which of the following statements is true? A) Side A is hypertonic to side B. B) Side A is hypotonic to side B. C) Side A is hypertonic to side B with respect to glucose. D) Side A is hypotonic to side B with respect to NaCl.

Side A is hypotonic to side B.

Which of the following provides the best evidence that cell-signaling pathways evolved early in the history of life? A) Cell-signaling pathways are seen in "primitive" cells such as bacteria and yeast. B) Bacteria and yeast cells signal each other in a process called quorum sensing. C) Signal transduction molecules identified in distantly related organisms are similar. D) Most signals in all types of cells are received by cell surface receptors.

Signal transduction molecules identified in distantly related organisms are similar.

Which of the following statements describes a major difference between mitosis and meiosis I in a diploid organism? A) Sister chromatids separate in mitosis, while homologous pairs of chromosomes separate in meiosis I. B) Sister chromatids separate in mitosis, while homologous pairs of chromosomes separate in meiosis II. C) DNA replication takes place prior to mitosis, but not before meiosis I. D) Only meiosis I results in daughter cells that contain identical genetic information.

Sister chromatids separate in mitosis, while homologous pairs of chromosomes separate in meiosis I.

Which of the following statements is true about proteins? A) Denaturation leads to bond disruption, and the molecule turns into liquid B) Denaturation is always irreversible C) Final folded structure can reveal the steps of protein folding D) Some proteins form a complete 3-D structure only when they interact with their targets

Some proteins form a complete 3-D structure only when they interact with their targets

A friend of yours calls to say that his car would not start this morning. He asks for your help. You say that you think the battery must be dead. If so, then jump-starting the car from a good battery will solve the problem. In doing so, you are ________. A) testing a theory for why the car will not start B) making observations to inspire a theory for why the car will not start C) stating a hypothesis and using that hypothesis to make a testable prediction D) comparing multiple hypotheses for why the car will not start

Stating a hypothesis and using that hypothesis to make a testable prediction

The receptors for steroid hormones are located inside the cell instead of the membrane surface like most other signal receptors. How do steroids gain access to their receptors? A) Steroid hormone receptors undergo conformational changes that relocate them on the membrane surface. B) Both steroid hormones and their receptors are produced by the same cells. C) Steroid hormones are lipid soluble, so they can readily diffuse through the lipid bilayer of the cell membrane. D) Steroid hormones first bind to a steroid activator and this complex is transported across the cell membrane by a steroid transport protein.

Steroid hormones are lipid soluble, so they can readily diffuse through the lipid bilayer of the cell membrane.

In a metabolic pathway, succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by malonic acid, a substance that resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the amount of succinate molecules to those of malonic acid reduces the inhibitory effect of malonic acid. Which of the following statements correctly describes the role played by molecules described in the reaction? A) Succinate dehydrogenase is the enzyme, and fumarate is the substrate in the reaction. B) Succinate dehydrogenase is the enzyme, and malonic acid is the substrate in the reaction. C) Succinate is the substrate, and fumarate is the product in the reaction. D) Fumarate is the product, and malonic acid is a noncompetitive inhibitor in the reaction.

Succinate is the substrate, and fumarate is the product in the reaction.

Most cells CANNOT HARNESS HEAT to perform work because ________. A) heat is not a form of energy B) temperature is usually uniform throughout a cell C) heat can never be used to do work D) heat must remain constant during work

TEMPERATURE is usually UNIFORM throughout a cell

What is meant by the description "antiparallel" regarding the two strands that make up the DNA double helix? A) The double helix structure of DNA creates nonparallel strands. B) The 5'; to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand. C) Base pairings create unequal spacing between the two DNA strands. D) One strand contains only purines and the other contains only pyrimidines.

THE 5' to 3' direction....

Where are ATP SYNTHASE COMPLEXES located in plant cells? A) thylakoid membrane only B) inner mitochondrial membrane only C) thylakoid membrane and inner mitochondrial membrane D) thylakoid membrane and plasma membrane

THYLAKOID membrane and INNER MITOCHONDRIAL

Which of the following processes occurs in PROKARYOTES BUT NOT EUKARYOTES? A) post-transcriptional splicing B) transcription and translation occur simultaneously C) translation in the absence of a ribosome D) gene splicing

TRANSCRIPTION and TRANSLATION occur SIMUTANEOUSLY

Which process is most directly driven by light energy? A) creation of a pH gradient by pumping protons across the thylakoid membrane B) reduction of NADP+ molecules C) transfer of energy from pigment molecule to pigment molecule D) ATP synthesis

TRANSFER OF ENERGY FROM PIGMENT

Which of the following statements is true about PROTEIN SYNTHESIS IN PROKARYOTES A) Extensive RNA processing is required before prokaryotic transcripts can be translated. B) Translation can begin while transcription is still in progress. C) Prokaryotic cells have complicated mechanisms for targeting proteins to the appropriate cellular organelles. D) Unlike eukaryotes, prokaryotes require no initiation or elongation factors.

TRANSLATION can being when transcription is still in progress

Once a PEPTIDE BOND has been formed between the amino acid attached to the tRNA in the P site and the amino acid associated with the tRNA in the A site, what process occurs NEXT? A) translocation B) reading of the next codon of mRNA C) initiation D) The codon-anticodon hydrogen bonds holding the tRNA in the A site are broken.

TRANSLOCATION

Which of the following would be most appropriate method to observe and measure the SIZE of RIBOSOMES in a eukaryotic cell? A) a hand lens (magnifying glass) B) standard light microscopy C) scanning electron microscopy D) transmission electron microscopy

TRANSMISSION ELECTRON

Which of the following are qualities of any good scientific hypothesis? I. It is testable. II. It is falsifiable. III. It produces quantitative data. IV. It produces results that can be replicated.

Testable and falsifiable I and II

A mutation that knocks out the GTPase activity of a G protein would have what effect on a cell? A) The concentration of available GTP would decrease. B) The number of G proteins in the cell would increase. C) The G protein would be inactivated by a G protein-coupled receptor/signal molecule complex. D) The G protein would always be active.

The G protein would always be activ

Which of the following statements correctly describes the difference between the leading and the lagging strands of DNA during DNA replication? A) The leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction. B) The leading strand is synthesized by adding nucleotides to the 3'end of the growing strand, and the lagging strand is synthesized by adding nucleotides to the 5'; end. C) The lagging strand is synthesized continuously, whereas the leading strand is synthesized in short fragments that are ultimately stitched together. D) The leading strand is synthesized at twice the rate of the lagging strand.

The LEADING strand is synthesized in the SAME DIRECTION as the movement of the replication FORK, and the lagging strand is synthesized in the opposite direction

What will happen to a red blood cell (RBC), which has an internal ion content of about 0.9%, if it is placed into a beaker of pure water? A) The cell would shrink because the water in the beaker is hypotonic relative to the cytoplasm of the RBC. B) The cell would shrink because the water in the beaker is hypertonic relative to the cytoplasm of the RBC. C) The cell would swell because the water in the beaker is hypotonic relative to the cytoplasm of the RBC. D) The cell will remain the same size because the solution outside the cell is isotonic.

The cell would swell because the water in the beaker is hypotonic relative to the cytoplasm of the RBC. SWELL

Which of the following statements describes the events of apoptosis? A) The cell dies, it is lysed, its organelles are phagocytized, and its contents are recycled. B) The cell's DNA and organelles become fragmented, the cell dies, and it is phagocytized. C) The cell's DNA and organelles become fragmented, the cell shrinks and forms blebs, and the cell's parts are packaged in vesicles that are digested by specialized cells. D) The cell's nucleus and organelles are lysed, and then the cell enlarges and bursts.

The cell's DNA and organelles become fragmented, the cell shrinks and forms blebs, and the cell's parts are packaged in vesicles that are digested by specialized cells.

Which of the following statements describes the chromosomal makeup of each daughter cell after telophase of meiosis I? A) The cells are diploid, and the chromosomes are each composed of a single chromatid. B) The cells are diploid, and the chromosomes are each composed of two chromatids. C) The cells are haploid, and the chromosomes are each composed of a single chromatid. D) The cells are haploid, and the chromosomes are each composed of two chromatids.

The cells are haploid, and the chromosomes are each composed of two chromatids.

How do cells at the completion of meiosis compare with cells that are in prophase of meiosis I? A) The cells have half the number of chromosomes and half the amount of DNA. B) The cells have the same number of chromosomes and half the amount of DNA. C) The cells have half the number of chromosomes and one-fourth the amount of DNA. D) The cells have half the amount of cytoplasm and twice the amount of DNA.

The cells have half the number of chromosomes and one-fourth the amount of DNA.

Which of the following statements regarding gene linkage is correct? A) The closer two genes are on a chromosome, the lower the probability that a crossover will occur between them. B) The observed frequency of recombination of two genes that are far apart from each other has a maximum value of 100%. C) All of the traits that Mendel studied—seed color, pod shape, flower color, and others—are due to genes linked on the same chromosome. D) Linked genes are found on different chromosomes.

The closer two genes are on a chromosome, the lower the probability that a crossover will occur between them.

In the U-tube experiment illustrated above, which of the following statements correctly describes side B at equilibrium? A) The concentration of NaCl and glucose will decrease, and the water level will increase. B) The concentration of NaCl will increase, the concentration of glucose will decrease, and the water level will increase. C) The concentration of NaCl will increase, the concentration of glucose will decrease, and the water level will decrease. D) The concentration of NaCl and glucose will increase, and the water level will decrease.

The concentration of NaCl will increase, the concentration of glucose will decrease, and the water level will increase. idi

Consider two solutions: solution X has a pH of 4; solution Y has a pH of 7. From this information, we can reasonably conclude that ________. A) solution Y has no free hydrogen ions (H+) B) the concentration of hydrogen ions in solution Y is 1000 times as great as the concentration of hydrogen ions in solution X C) the concentration of hydrogen ions in solution X is 3 times as great as the concentration of hydrogen ions in solution Y D) the concentration of hydrogen ions in solution X is 1000 times as great as the concentration of hydrogen ions in solution Y

The concentration of hydrogen ions in solution X is 1000 times as great as the concentration of solution Y

Recall that eggs from the same female were exposed to each of the eight treatments used. This aspect of the experimental design tested which of the following hypotheses? A) The longer day lengths of summer trigger the development of twig-like caterpillars. B) Differences in air pressure, due to elevation, trigger the development of different types of caterpillars. C) Differences in diet trigger the development of different types of caterpillars. D) The differences are genetic. A female will either produce all flowerlike caterpillars or all twig-like caterpillars.

The differences are genetic. A female will either produce all flowerlike caterpillars or all twig-like

Hutchinson-Gilford progeria is an exceedingly rare human genetic disorder in which there is very early senility and death, usually from coronary artery disease, at an average age of 13 years. Patients, who look very old even as children, do not live to reproduce. Which of the following statements represents the most likely assumption regarding this disorder? A) The disease is autosomal dominant. B) The disorder will increase in frequency in successive generations within a family. C) The disorder may be due to mutation in a single protein-coding gene. D) Each patient will have had at least one affected grandparent or parent.

The disorder may be due to mutation in a single protein-coding gene.

Fransisco Redi In both experiments, flies appeared in all of the open jars and only in the open jars. Which one of the following statements is correct? A) The experiment was inconclusive because Redi used only one kind of meat. B) The experiment was inconclusive because it did not run long enough. C) The experiment supports the hypothesis that spontaneous generation occurs in rotting meat. D) The experiment supports the hypothesis that maggots arise only from eggs laid by adult flies.

The experiment supports the hypothesis that maggots arise only from eggs laid by adult flies

Map units on a linkage map cannot be relied upon to calculate physical distances on a chromosome for which of the following reasons? A) The frequency of crossing over varies along the length of the chromosome. B) The relationship between recombination frequency and map units is different in every individual. C) Physical distances between genes change during the course of the cell cycle. D) The gene order on the chromosomes is slightly different in every individual.

The frequency of crossing over varies along the length of the chromosome.

When Thomas Hunt Morgan crossed his red-eyed F1 generation flies to each other, the F2 generation included both red- and white-eyed flies. Remarkably, all the white-eyed flies were male. What was the explanation for this result? A) The gene involved is located on the Y chromosome. B) The gene involved is located on the X chromosome. C) The gene involved is located on an autosome, but only in males. D) Other male-specific factors influence eye color in flies.

The gene involved is located on the X chromosome.

Mendel crossed yellow-seeded and green-seeded pea plants and then allowed the offspring to self-pollinate to produce an F2 generation. The results were as follows: 6,022 yellow and 2,001 green (8,023 total). Which of the following statements correctly describes the relationship of the allele for green seeds to the allele for yellow seeds? A) The green allele is dominant to the yellow allele. B) The two alleles exhibit incomplete dominance. C) The green allele is recessive to the yellow allele. D) The two alleles are codominant.

The green allele is recessive to the yellow allele.

Exposing inner mitochondrial membranes to ultrasonic vibrations will disrupt the membranes. However, the fragments will reseal "inside out." The little vesicles that result can still transfer electrons from NADH to oxygen and synthesize ATP. Which of the following statements about these inside-out membrane vesicles is true? A) The inside of the vesicles will become acidic when NADH is added. B) The inside of the vesicles will become alkaline when NADH is added. C) ATP will be produced from ADP and i in the interior of the vesicle. D) The vesicles will pump protons out of the interior of the vesicle to the exterior using energy from ATP hydrolysis.

The inside of the vesicles will become acidic when NADH is added.

Which of the following statements about independent assortment or segregation is correct? A) The law of independent assortment describes the behavior of two or more genes relative to one another. B) The law of segregation describes the behavior of two or more genes relative to one another. C) The law of independent assortment is accounted for by observations of prophase I of meiosis. D) The law of segregation is accounted for by anaphase of mitosis.

The law of independent assortment describes the behavior of two or more genes relative to one another.

Using your knowledge of the structure of eukaryotic cells, identify the statement below that best explains how internal membranes and the organelles of cells may be involved in Gaucher disease. A) The mitochondria are most likely defective and do not produce adequate amounts of ATP needed for cellular energy. B) The rough endoplasmic reticulum contains too many ribosomes, which results in an overproduction of the enzyme involved in lipid breakdown. C) The lysosomes lack sufficient amounts of enzymes necessary for the metabolism of lipids. D) The Golgi apparatus produces vesicles with faulty membranes, which fail to be transported to the plasma membrane for secretion.

The lysosomes lack sufficient amounts of enzymes necessary for the metabolism of

How do you explain the results of Wilson's experiments? A) The two species of sponge had different enzymes that functioned in the reassembly process. B) The molecules responsible for cell-cell adhesion (cell junctions) were irreversibly destroyed during the experiment. C) The molecules responsible for cell-cell adhesion (cell junctions) differed between the two species of sponge. D) One cell functioned as an organizer for each organism, thereby attracting only cells of the same species.

The molecules responsible for cell-cell adhesion (cell junctions) differed between the two species of sponge.

Which of the following statements correctly describes the difference between ATP and the nucleotides used during DNA synthesis? A) The nucleotides have the sugar deoxyribose; ATP has the sugar ribose. B) The nucleotides have two phosphate groups; ATP has three phosphate groups. C) ATP contains three high-energy bonds; the nucleotides have two. D) ATP is found only in human cells; the nucleotides are found in all animal and plant cells.

The nucleotides have a SUGAR DEOXYRIBOSE; ATP has the sugar ribose

Agrobacterium infects plants and causes them to form tumors. You determine that tumor formation requires a large amount of the plant's energy for tissue formation. How might this change the number of offspring a plant produces, and what is the most likely explanation for this change? A) The number of offspring should increase because in general, illness increases the reproductive output of organisms. B) The number of offspring should increase because the bacteria will provide energy for the plant. C) The number of offspring should decrease because the plant will divert energy from reproduction to tumor formation. D) There should be no effect of infection on offspring production because energy for reproduction is independent of infection.

The number of offspring should decrease because the plant will divert energy from reproduction to tumor formation

The cities of Portland, Oregon, and Minneapolis, Minnesota, are at about the same latitude, but Minneapolis has much hotter summers and much colder winters than Portland. Why? A) They are not at the same exact latitude. B) The ocean near Portland moderates the temperature. C) Fresh water is more likely to freeze than salt water. D) Minneapolis is much windier, due to its location in the middle of North America.

The ocean near Portland moderates the temperature

Biological systems use free energy based on empirical data that all organisms require a constant energy input. The first law of thermodynamics states that energy can be neither created nor destroyed. For living organisms, which of the following statements is an important consequence of this first law? A) The energy content of an organism is constant except for when its cells are dividing. B) The organism must ultimately obtain all the necessary energy for life from its environment. C) The entropy of an organism decreases with time as the organism grows in complexity. D) Organisms are unable to transform energy from the different states in which it can exist.

The organism must ultimately obtain all the necessary energy for life from its environment.

When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs? A) The pH of the matrix increases. B) ATP synthase pumps protons by active transport. C) The electrons gain free energy. D) NAD+ is oxidized.

The pH of the matrix increases.

A patient was involved a serious accident and lost a large quantity of blood. In an attempt to replenish body fluids, distilled water—equal to the volume of blood lost—is added to the blood directly via one of his veins. What will be the most probable result of this transfusion? A) The patient's red blood cells will shrivel up because the blood has become hypotonic compared to the cells. B) The patient's red blood cells will swell and possibly burst because the blood has become hypotonic compared to the cells. C) The patient's red blood cells will shrivel up because the blood has become hypertonic compared to the cells. D) The patient's red blood cells will burst because the blood has become hypertonic compared to the cells.

The patient's red blood cells will swell and possibly burst because the blood has become hypotonic compared to the cells. swell

Use the following information to answer the question. A plantlike organism on the planet Pandora can have three recessive genetic traits: bluish leaves, due to an allele (a) of gene A; a feathered stem, due to an allele (b) of gene B; and hollow roots due to an allele (c) of gene C. The three genes are linked and recombine. A geneticist performed a testcross with an organism that had been found to be heterozygous for the three recessive traits, and she was able to identify progeny of the following phenotypic distribution (+ = wild type): Phenotypes Leaves Stems Roots Number 1 a + + 14 2 a + c 0 3 a b + 32 4 a b c 440 5 + b + 0 6 + b c 16 7 + + c 28 8 + + + 470 Total 1000 What is the greatest benefit of having used a testcross for this experiment? A) The homozygous recessive parents are obvious to the naked eye. B) The homozygous parents are the only ones whose crossovers make a difference. C) The phenotypes of the progeny reveal the allelic content of the gamete from the heterozygous parent. D) All of the progeny will be heterozygous.

The phenotypes of the progeny reveal the allelic content of the gamete from the heterozygous parent.

What does it mean to say that a signal is transduced? A) The signal enters the cell directly and binds to a receptor inside. B) The physical form of the signal changes as it passes from the cell membrane to the ultimate intracellular target. C) The signal is amplified, such that even one signal molecule evokes a large response. D) The signal triggers a sequence of phosphorylation events inside the cell.

The physical form of the signal changes as it passes from the cell membrane to the ultimate intracellular target.

How do phospholipids interact with water molecules? A) The polar heads avoid water; the nonpolar tails attract water (because water is polar and opposites attract). B) Phospholipids do not interact with water because water is polar and lipids are nonpolar. C) The polar heads interact with water; the nonpolar tails do not. D) Phospholipids dissolve in water.

The polar heads interact with water; the nonpolar tails do not.

If you were to add one of the eight citric acid cycle intermediates to the culture medium of yeast growing in the laboratory, what do you think would happen to the rates of ATP and carbon dioxide production? A) There would be no change in ATP production, but the rate of carbon dioxide production would increase. B) The rates of ATP production and carbon dioxide production would both increase. C) The rate of ATP production would increase, but the rate of carbon dioxide production would decrease. D) The rates of ATP and carbon dioxide production would both decrease.

The rates of ATP production and carbon dioxide production would both increase.

Which of the following statements correctly describes any chemical reaction that has reached equilibrium? A) The concentrations of products and reactants are equal. B) The reaction is now irreversible. C) Both forward and reverse reactions have halted. D) The rates of the forward and reverse reactions are equal.

The rates of the FORWARD and reverse reactions are EQUAL

Which of the following statements is true for all exergonic reactions? A) The products have more total energy than the reactants. B) The reaction proceeds with a net release of free energy. C) The reaction goes only in a forward direction: all reactants will be converted to products, but no products will be converted to reactants. D) A net input of energy from the surroundings is required for the reactions to proceed.

The reaction proceeds with a net release of free energy.

Which of the following statements is true of steroid receptors? A) The receptor molecules are themselves lipids or glycolipids. B) The receptor may be inside the nucleus of a target cell. C) The unbound steroid receptors are quickly recycled by lysosomes. D) Steroid receptors are typically bound to the external surface of the nuclear membrane.

The receptor may be inside the nucleus of a target cell.

What would be observed by live-cell fluorescence microscopy immediately after HIV entry if HIV is endocytosed first, and then later fuses with the endocytotic vesicle membrane? A) A spot of red fluorescence will be visible on the infected cell's plasma membrane, marking the site of membrane fusion and HIV entry. B) The red fluorescent dye-labeled lipids will appear in the infected cell's interior. C) A spot of red fluorescence will diffuse in the infected cell's cytoplasm. D) A spot of red fluorescence will remain outside the cell after delivering the viral capsid.

The red fluorescent dye-labeled lipids will appear in the infected cell's interior. no spot

During meiosis, a defect occurs in a cell that results in the failure of spindle microtubules binding at the kinetochores. Which of the following statements describes the most likely result of such a defect? A) New microtubules with more effective binding capabilities to kinetochores will be synthesized to compensate for the defect. B) Excessive cell divisions will occur resulting in cancerous tumors and an increase in the chromosome numbers known as polyploidy. C) The defect will be bypassed in order to ensure normal chromosome distribution in the new cells. D) The resulting cells will not receive the correct number of chromosomes in the gametes, a condition known as aneuploidy.

The resulting cells will not receive the correct number of chromosomes in the gametes, a condition known as aneuploidy.

Imagine that there are 25 different species of protists living in a tide pool. Some of these species reproduce both sexually and asexually, and some of them can reproduce only asexually. The pool gradually becomes infested with disease-causing viruses and bacteria. Which species are more likely to thrive in the changing environment? A) The sexually reproducing species is likely to thrive. B) The asexually reproducing species is likely to thrive. C) Sexually and asexually reproducing species are equally likely to thrive. D) Neither species will be able to thrive.

The sexually reproducing species is likely to thrive.

In a life cycle such as that shown in part III of the figure above, if the zygote's chromosome number is ten, which of the following statements will be true? A) The sporophyte's chromosome number per cell is ten and the gametophyte's is five. B) The sporophyte's chromosome number per cell is five and the gametophyte's is ten. C) The sporophyte and gametophyte each have ten chromosomes per cell. D) The sporophyte and gametophyte each have five chromosomes per cell.

The sporophyte's chromosome number per cell is ten and the gametophyte's is five.

Which of the following statements is true for a system at chemical equilibrium? A) The system consumes energy at a steady rate. B) The system releases energy at a steady rate. C) The kinetic energy of the system is zero. D) The system can do no work.

The system can do no work.

Which of the following statements describes a likely effect of a drug designed that inhibits the cellular response to testosterone? A) The cytoplasmic levels of cAMP would decrease. B) The transcription of certain genes would decrease. C) The cytosolic calcium concentration would increase. D) The activity of G proteins would decrease.

The transcription of certain genes would decrease.

Which of the following statements would explain a testcross involving F1 dihybrid flies in which more parental-type offspring than recombinant-type offspring are produced? A) The two genes are closely linked on the same chromosome. B) The two genes are linked but on different chromosomes. C) Recombination did not occur in the cell during meiosis. D) Both of the characters are controlled by more than one gene.

The two genes are closely linked on the same chromosome.

What does a recombination frequency of 50% indicate? A) The two genes are likely to be located on different chromosomes. B) All of the offspring have combinations of traits that match one of the two parents. C) The genes are located on sex chromosomes. D) Abnormal meiosis has occurred.

The two genes are likely to be located on different chromosomes.

How does a scientific theory differ from a scientific hypothesis? A) Theories are proposed to test scientific hypotheses. B) Theories are usually an explanation for a more general phenomenon; hypotheses typically address more specific issues. C) Hypotheses are usually an explanation for a more general phenomenon; theories typically address more specific issues. D) Confirmed theories become scientific laws; hypotheses become theories.

Theories are usually an explanation for a more general phenomenon; hypotheses typicaly address more specific issues

The cell walls of bacteria, fungi, and plant cells, and the extracellular matrix of animal cells are all external to the plasma membrane. Which of the following characteristics are common to all of these extracellular structures? A) They must block water and small molecules to regulate the exchange of matter and energy with their environment. B) They must provide a rigid structure that maintains an appropriate ratio of cell surface area to volume. C) They are constructed of materials that are synthesized in the cytoplasm and then transported out of the cell for assembly. D) They are composed of a mixture of lipids and nucleotides.

They are constructed of materials that are synthesized in the cytoplasm and then transported out of the cell for assembly.

Which of the following statements describes a common characteristic of catabolic pathways? A) They combine small molecules into larger, more energy-rich molecules. B) They require energy from ATP hydrolysis to break down polymers into monomers. C) They are endergonic and release energy that can be used for cellular work. D) They are exergonic and provide energy that can be used to produce ATP from ADP and i.

They are exergonic and provide energy that can be used to produce ATP from ADP and i.

Exposure of zebrafish nuclei to cytosol isolated from eggs at metaphase of mitosis resulted in phosphorylation of NEP55 and L68 proteins by cyclin-dependent kinase 2. NEP55 is a protein of the inner nuclear membrane, and L68 is a protein of the nuclear lamina. What is the most likely role of phosphorylation of these proteins in the process of mitosis? A) They enable the attachment of the spindle microtubules to kinetochore regions of the centromere. B) They are involved in chromosome condensation. C) They are involved in the disassembly of the nuclear envelope. D) They assist in the migration of centrosomes to opposite sides of the nucleus.

They are involved in the disassembly of the nuclear envelope

Which of the following statements correctly describes the reason that closely linked genes are typically inherited together? A) They are located close together on the same chromosome. B) The number of genes in a cell is greater than the number of chromosomes. C) Alleles are paired together during meiosis. D) Genes align that way during metaphase I of meiosis.

They are located close together on the same chromosome.

Protein kinases are enzymes that transfer the terminal phosphate from ATP to an amino acid residue on the target protein. Many are located on the plasma membrane as integral membrane proteins or peripheral membrane proteins. What purpose may be served by their plasma membrane localization? A) ATP is more abundant near the plasma membrane. B) They can more readily encounter and phosphorylate other membrane proteins. C) Membrane localization lowers the activation energy of the phosphorylation reaction. D) They flip back and forth across the membrane to access target proteins on either side.

They can more readily encounter and phosphorylate other membrane proteins.

Which of the following characteristics do homologous chromosomes exhibit? A) They carry information for different traits. B) They carry information for the same traits. C) They carry the same alleles. D) They align on the metaphase plate in meiosis II.

They carry information for the same traits.

What is a primary function of transcription factors? A) They regulate the synthesis of DNA in response to a signal. B) They convert ATP into cAMP. C) They control gene expression. D) They regulate the release of calcium from the endoplasmic reticulum.

They control gene expression.

What role do phosphatases play in signal transduction pathways? A) They transfer a phosphate group from one protein in the pathway to the next molecule in the series. B) They activate protein kinases by phosphorylation. C) They amplify the second messenger cAMP. D) They inactivate protein kinases to turn off signal transduction.

They inactivate protein kinases to turn off signal transduction.

Which of the following statements is true about buffer solutions? A) They maintain a constant pH of 7. B) They maintain a constant pH when acids are added to them but not when bases are added to them. C) They fluctuate in pH when either acids or bases are added to them. D) They maintain a relatively constant pH when either acids or bases are added to them.

They maintain a RELATIVELY constant pH when either acids or bases are added to them

What was the most significant conclusion that Gregor Mendel drew from his experiments with pea plants? A) There is considerable genetic variation in garden peas. B) Traits are inherited in discrete units and are not the result of "blending." C) Recessive genes occur more frequently in the F1 generation than do dominant ones. D) Genes are composed of DNA.

Traits are inherited in discrete units and are not the result of "blending."

Which of the following statements correctly describes how Mendel accounted for the observation that traits had disappeared in the F1 generation and then reappeared in the F2 generation? A) New mutations were frequently generated in the F2 progeny, causing traits that had been lost in the F1 to reappear in the F2. B) The mechanism controlling the appearance of traits was different between the F1 and the F2 plants. C) Traits can be dominant or recessive, and the recessive traits were "hidden" by the dominant ones in the F1. D) Members of the F1 generation had only one allele for each trait, but members of the F2 had two alleles for each trait.

Traits can be dominant or recessive, and the recessive traits were "hidden" by the dominant ones in the F1.

Which of the following is an example of monosomy in humans? A) Turner syndrome B) Klinefelter syndrome C) Down syndrome D) trisomy X

Turner syndrome

Why are C4 plants able to photosynthesize with no apparent photorespiration? A) They do not participate in the Calvin cycle. B) They use PEP carboxylase to initially fix CO2. C) They conserve water more efficiently. D) They exclude oxygen from their tissues.

USE PEP CARBOXYLASE

Which diagram represents anaphase II of meiosis? A) I B) III C) IV D) V

Centromeres of sister chromatids disjoin and chromatids separate. A) III B) IV C) V D) VII

VII

Which of the following statements correctly describes OSMOSIS? A) Osmosis only takes place in red blood cells. B) Osmosis is an energy-demanding or "active"process. C) In osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration. D) In osmosis, solutes move across a membrane from areas of lower water concentration to areas of higher water concentration.

WATER MOVES across membrane from LOWER solute to HIGHER solute

Nucleotides can be radiolabeled before they are incorporated into newly synthesized DNA and, therefore, can be assayed to track their incorporation. In a set of experiments, a student- faculty research team used labeled T nucleotides and introduced these into a CULTURE OF DIVIDING HUMAN CELLS at specific times. Which of the following questions might be answered by using the method described? A) How many cells are produced by the culture per hour? B) What is the length of the S phase of the cell cycle? C) How many picograms of DNA are made per cell cycle? D) When do spindle fibers attach to chromosomes?

WHAT is the LENGTH OF S PHASE

When are atoms most stable? A) when they have the fewest possible valence electrons B) when they have the maximum number of unpaired electrons C) when all of the electron orbitals in the valence shell are filled D) when all electrons are paired

When all of the electron orbital in the valence shell are filled

HERSHEY AND CHASE used a DNA-based virus for their work. How might the results have been different if they had used an RNA virus? A) With an RNA virus, radioactive protein would have been in the final pellet. B) With an RNA virus, radioactive RNA would have been in the final pellet. C) With an RNA virus, neither sample would have had a radioactive pellet. D) With an RNA virus, the protein shell would have been radioactive in both samples.

With an RNA virus, radioactive (RNA) would have been in the FINAL PELLET

Red-green color blindness is a sex-linked recessive trait in humans. Two people with normal color vision have a color-blind son. What are the genotypes of the parents? A) XnXn and XnY B) XNXN and XnY C) XNXN and XNY D) XNXn and XNY

XNXn and XNY

Can the atomic mass of an element vary? A) No, it is fixed; otherwise a new element will be formed. B) Yes. Adding or losing electrons will substantially change the atomic mass. C) Yes. Adding or losing protons will change the atomic mass without forming a different element. D) Yes. Adding or losing neutrons will change the atomic mass without forming a different element.

Yes, adding or losing NEUTRONS will change the atomic mass without forming a different element

Which of the following phrases correctly defines what one map unit is? A) the physical distance between two linked genes B) a 1% frequency of recombination between two genes C) 1 nanometer of distance between two genes D) the recombination frequency between two genes assorting independently

a 1% frequency of recombination between two genes

MALTOSE is a disaccharide that can easily be digested into glucose molecules. The GLYCOSIDIC linkage between glucose molecules in maltose is ________. A) β 1—4 B) α 1—2 C) α 1—4 D) β 1—2

a 1-4

Which of the following processes occurs in EUKARYOTIC GENE EXPRESSION? A) mRNA, tRNA, and rRNA are translated. B) RNA polymerase binds to the terminator sequence. C) A cap is added to the 5′ end of the mRNA. D) RNA polymerase requires tRNA to elongate the molecule.

a CAP is added to the 5' end of the mRNA

The GENETIC CODE IS ESSENTIALLY THE SAME for all organisms. From this, one can logically assume which of the following statements to be true? A) A gene from an organism can theoretically be expressed by any other organism. B) DNA was the first genetic material. C) The same codons in different organisms translate into different amino acids. D) Different organisms have different types of amino acids.

a GENE from an organism can THEORETICALLY be expressed by ANY OTHER ORGANISM

Which of the following can be attributed to water's high specific heat? A) Oil and water do not mix well. B) A lake heats up more slowly than the air around it. C) Ice floats on water. D) Sugar dissolves in hot tea faster than in iced tea.

a LAKE heats up more slowly than the air around it

Which of the following effects can occur because of the high surface tension of water? A) Lakes cannot freeze solid in winter, despite low temperatures. B) A raft spider can walk across the surface of a small pond. C) Organisms can resist temperature changes, although they give off heat due to chemical reactions. D) Sweat can evaporate from the skin, helping to keep people from overheating.

a RAFT SPIDER can walk across the surface of a small pond

Which of the following DNA mutations is most likely to DAMAGE THE PROTEIN it specifies? A) a base-pair deletion B) an addition of three nucleotides C) a substitution in the last base of a codon D) a codon deletion

a base pair DELETION

What results from the chemical reaction in the illustration? The reactants have no charge. A) a cation with a net charge of +1 and an anion with a net charge of +1 B) a cation with a net charge of -1 and an anion with a net charge of -1 C) a cation with a net charge of -1 and an anion with a net charge of +1 D) a cation with a net charge of +1 and an anion with a net charge of -1

a cation with a net charge of +1, and an anion with a net charge of -1

The nuclear lamina is an array of intermediate filaments that line the inner side of the nuclear membrane. If a chemical treatment caused the lamina to disassemble, what would you expect to be the most likely immediate consequence? A) closing of nuclear pores B) the inability of the nucleus to divide during cell division C) a loss of genetic information from chromosomes D) a change in the shape of the nucleus

a change in the shape of the nucleus

Chemical equilibrium is relatively rare in living cells because metabolic pathways are interconnected. Which of the following statements describes an example of a reaction that may be at chemical equilibrium in a cell? A) an exergonic reaction in which the free energy at equilibrium is higher than the energy content of the reaction at any point away from equilibrium B) an exergonic reaction in which the entropy change in the cell is precisely balanced by an opposite entropy change in the cell's surroundings C) a chemical reaction in which neither the reactants nor the products are being produced or consumed in any metabolic pathway at that time in the cell D) an endergonic reaction in an active metabolic pathway where the energy for that reaction is supplied only by heat from the environment

a chemical reaction in which neither the reactants nor the products are being produced or consumed in any metabolic pathway at that time in the cell

A single base substitution mutation is likely to have a LESS DELETERIOUS effect when the base change exhibits which of the following results? A) a stop codon B) a codon that specifies the same amino acid as the original codon C) an amino acid substitution that alters the tertiary structure of the protein D) an amino acid substitution at the active site of an enzyme

a codon that specifies the same amino acid as the ORIGINAL CODON

Zinc, an essential trace element for most organisms, is present in the active site of the enzyme carboxypeptidase. The zinc most likely functions as ________. A) a noncompetitive inhibitor of the enzyme B) an allosteric activator of the enzyme C) a cofactor necessary for enzyme activity D) a coenzyme derived from a vitamin

a cofactor necessary for enzyme activity

All the organisms on your campus make up A) an ecosystem. B) a community. C) a population. D) a taxonomic domain.

a community

The force driving simple diffusion is ________, while the energy source for active transport is ________. A) a concentration gradient; ADP B) a concentration gradient; ATP hydrolysis C) transmembrane pumps; an electrochemical gradient D) phosphorylated carrier proteins; ATP

a concentration gradient; ATP hydrolysis

When nucleotides polymerize to form a nucleic acid, ________. A) a covalent bond forms between the sugar of one nucleotide and the phosphate of a second B) a hydrogen bond forms between the sugar of one nucleotide and the phosphate of a second C) covalent bonds form between the bases of two nucleotides D) hydrogen bonds form between the bases of two nucleotides

a covalent bond forms between the sugar of one nucleotide and the phosphate of a second

Which of the following types of mutation, resulting in an ERROR in the mRNA just after the AUG start of translation, is likely to have the MOST SERIOUS effect on the polypeptide product? A) a deletion of a codon B) a deletion of two nucleotides C) a substitution of the third nucleotide in an ACC codon D) a substitution of the first nucleotide of a GGG codon

a deletion of CODON

If an adult person has a faulty version of the human analog to ced-4 of the nematode, which of the following is most likely to result? A) activation of a developmental pathway found in the worm but not in humans B) a form of cancer in which there is insufficient apoptosis C) formation of molecular pores in the mitochondrial outer membrane D) excess skin loss

a form of cancer in which there is insufficient apoptosis

The SRY gene is best described as ________. A) a gene present on the X chromosome that triggers female development B) an autosomal gene that is required for the expression of genes on the Y chromosome C) a gene present on the Y chromosome that triggers male development D) an autosomal gene that is required for the expression of genes on the X chromosome

a gene present on the Y chromosome that triggers male development

Which of the following factors would tend to increase membrane fluidity? A) a greater proportion of unsaturated phospholipids B) a greater proportion of saturated phospholipids C) a lower temperature D) a relatively high protein content in the membrane

a greater proportion of unsaturated phospholipid

What is a syndrome? A) a characteristic facial appearance B) a trait that leads to cancer at some stage in life C) a group of traits typically found in conjunction with a particular chromosomal aberration or gene mutation D) a specific characteristic that appears in conjunction with one specific aneuploidy

a group of traits typically found in conjunction with a particular chromosomal aberration or gene mutation

For lipids to be fluid at room temperature, they should have ________. A) single bonds only B) a higher number of glycerol molecules C) a higher number of cis double bonds D) a longer carbon chain

a higher number of cis double bonds

Which of the following correctly describes a Philadelphia chromosome? A) a human chromosome 22 that has had a specific translocation B) a human chromosome 9 that is found only in one type of cancer C) an animal chromosome found primarily in the mid-Atlantic area of the United States D) a chromosome found only in mitochondria

a human chromosome 22 that has had a specific translocation

The partial negative charge at one end of a water molecule is attracted to the partial positive charge of another water molecule. What is this attraction called? A) a covalent bond B) a hydrogen bond C) an ionic bond D) a van der Waals interaction

a hydrogen bond

Not all intercellular signals require transduction. Which one of the following signals would be processed without transduction? A) a lipid-soluble signal B) a signal that is weakly bound to a nucleotide C) a signal that binds to a receptor in the cell membrane D) a signal that binds to the extracellular matrix

a lipid-soluble signal

Each bond in carbon dioxide represents ________. O C O A) one resonating electron B) a pair of shared electrons C) two pairs of shared electrons D) a pair of protons

a pair of SHARED ELECTRONS

A glycosidic linkage is analogous to which of the following in proteins? A) an amino group B) a peptide bond C) a disulfide bond D) a β pleated sheet

a peptide bond

Which of the following is not one of Charles Darwin's observations? A) Individuals in a population vary in their traits. B) Many of the traits in an individual are heritable. C) A population avoids competition by producing only as many offspring as can successfully reproduce on their own. D) Species generally are adapted to their environments.

a population avoids competition by producing only as many offspring as can successfully reproduce their own

Which of the following structures would decrease the electrochemical gradient across a membrane? A) an aquaporin B) a proton pump C) a potassium channel D) both a proton pump and a sodium channel

a potassium channel

Which of the following mutations would be most likely to have a HARMFUL effect on an organism? A) a deletion of three nucleotides near the middle of a gene B) a single nucleotide deletion in the middle of an intron C) a single nucleotide deletion near the end of the coding sequence D) a single nucleotide insertion downstream of, and close to, the start of the coding sequence

a single nucleotide INSERTION DOWNSTREAM of and close to the start of the coding sequence

A human cell containing 22 autosomes and a Y chromosome is A) a sperm. B) an egg. C) a zygote. D) a somatic cell of a male.

a sperm.

A series of enzymes catalyze the reactions in the metabolic pathway X → Y → Z → A. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme. What is substance X? A) an allosteric inhibitor B) a substrate C) an intermediate D) the product

a substrate

Spherocytosis is a human blood disorder associated with a defective cytoskeletal protein in the red blood cells (RBCs). What do you suspect is the consequence of such a defect? A) abnormally shaped RBCs B) an insufficient supply of ATP in the RBCs C) an insufficient supply of oxygen-transporting proteins in the RBCs D) adherence of RBCs to blood vessel walls, causing plaque formation

abnormally shaped RBCs

For a species with a haploid number of 23 chromosomes, how many different combinations of maternal and paternal chromosomes are possible for the gametes based on the independent assortment of chromosomes during meiosis? A) 23 B) 46 C) about 1,000 D) about 8 million

about 8 million

Which one of the following is formed by the removal of a carbon (as CO2) from a molecule of pyruvate? A) ATP B) acetyl CoA C) citrate D) water

acetyl CoA

In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle. First, however, the pyruvate (1) loses a carbon, which is given off as a molecule of CO2, (2) is oxidized to form a two-carbon compound called acetate, and (3) is bonded to coenzyme A. Which of the following sets of products result from these reactions? A) acetyl CoA, O2, and ATP B) acetyl CoA, FADH2, and CO2 C) acetyl CoA, NADH, and CO2 D) acetyl CoA, NAD+, ATP, and CO2

acetyl CoA, NADH, and CO2

Protein kinase is an enzyme that functions in which of the following ways? A) as a second messenger molecule B) as a receptor for various signal molecules C) activates or inactivates other proteins by adding a phosphate group to them D) activates a G protein

activates or inactivates other proteins by adding a phosphate group to them

What is the name of the thermodynamic barrier that must be overcome before products are formed in a spontaneous reaction? A) entropy B) activation energy C) the equilibrium point D) free energy

activation energy

Protein phosphorylation is commonly involved with all of the following except A) activation of receptor tyrosine kinases. B) activation of protein kinase molecules. C) activation of G protein-coupled receptors. D) regulation of transcription by signaling molecules.

activation of G protein-coupled receptors.

In humans, clear gender differentiation occurs not at fertilization, but after the second month of gestation. Which of the following statements describes the first event of this differentiation? A) formation of testosterone in male embryos B) formation of estrogens in female embryos C) activation of SRY in male embryos and masculinization of the gonads D) activation of SRY in females and feminization of the gonads

activation of SRY in male embryos and masculinization of the gonads

Which of the following processes generally requires protein phosphorylation? A) activation of receptor tyrosine kinases B) activation of steroid hormone receptors C) activation of G protein-coupled receptors D) activation ligand-gated ion channels

activation of receptor tyrosine kinases

All female mammals have one active X chromosome per cell instead of two. What causes this to happen? A) activation of the XIST gene on the X chromosome that will become the Barr body B) activation of the BARR gene on one X chromosome, which then becomes inactive C) inactivation of the XIST gene on the X chromosome derived from the male parent D) attachment of methyl (-CH3) groups to the X chromosome that will remain active

activation of the XIST gene on the X chromosome that will become the Barr body

The evolution of one species into two or more species as a result of different populations becoming reproductively isolated from each other is best termed as ________. A) adaptive radiation B) creationism C) natural selection D) prototype

adaptive radiation

If an enzyme in solution is saturated with substrate, the most effective way to obtain a faster yield of products is to A) add more of the enzyme. B) heat the solution to 90°C. C) add more substrate. D) add a noncompetitive inhibitor.

add more of the enzyme.

POST-TRANSLATIONAL modifications of proteins may include which of the following processes? A) removal of introns B) addition of a 5′ cap C) addition of a poly-A tail D) addition of carbohydrates to form a glycoprotein

addition of CARBOHYDRATES to form glycoprotein

Which of the following factors will increase the rate of reaction in the forward direction? A) addition of nitrogen B) addition of ammonia C) addition of hydrogen D) addition of both nitrogen and hydrogen

addition of both hydrogen and nitrogen

Which of the following molecules is a part of ATP? A) adenosine B) cytosine C) guanine D) uracil

adenosine

Mendel's law of independent assortment has its basis in which of the following events of meiosis I? A) synapsis of homologous chromosomes B) crossing over of homologous pairs of chromosomes C) alignment of pairs of homologous chromosomes along the middle of the cell D) the division of cells at telophase

alignment of pairs of homologous chromosomes along the middle of the cell

Which of the following statements is true? A) mRNA is the only type of RNA found in the living system B) All forms of life employ the same genetic code C) A typical human liver cell has one set of chromosomes D) Organisms interact but do not affect their environment

all forms of life employ the same genetic code

Which of the following individuals will inherit an X-linked allele from a man who carries it? A) all of his daughters B) half of his daughters C) all of his sons D) all of his children

all of his daughters

Exposing inner mitochondrial membranes to ultrasonic vibrations will disrupt the membranes. However, the fragments will reseal "inside out." The little vesicles that result can still transfer electrons from NADH to oxygen and synthesize ATP. After the disruption, which components involved in oxidative phosphorylation must be present for electron transfer and ATP synthesis to still occur? A) only the electron transport system B) only the ATP synthase system C) all of the electron transport system and the proteins that add CoA to acetyl groups D) all of the electron transport system and ATP synthase

all of the electron transport system and ATP synthase

What kinds of cells carry out ATP synthesis by chemiosmosis? A) all cells, both prokaryotic and eukaryotic, exclusively using oxygen as the electron acceptor B) only animal cells in mitochondria, exclusively using oxygen as the electron acceptor C) only eukaryotic cells, both plant and animal, using either oxygen or other electron acceptors D) all respiring cells, both prokaryotic and eukaryotic, using either oxygen or other electron acceptors

all respiring cells, both prokaryotic and eukaryotic, using either oxygen or other electron acceptors

Gene S controls the sharpness of spines in a type of cactus. Cacti with the dominant allele, S, have sharp spines, whereas homozygous recessive ss cacti have dull spines. At the same time, a second gene, N, determines whether or not cactuses have spines. Homozygous recessive nn cactuses have no spines at all. A cross between a true-breeding sharp-spined cactus and a spineless cactus would produce ________. A) all sharp-spined progeny B) 50% sharp-spined, 50% dull-spined progeny C) 25% sharp-spined, 50% dull-spined, 25% spineless progeny D) It is impossible to determine the phenotypes of the progeny.

all sharp-spined progeny

A series of enzymes catalyze the reactions in the metabolic pathway X → Y → Z → A. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme. With respect to the enzyme that converts X to Y, substance A functions as ________. A) an allosteric inhibitor B) the substrate C) an intermediate D) a competitive inhibitor

allosteric inhibitor

High levels of citric acid inhibit the enzyme phosphofructokinase, a key enzyme in glycolysis. Citric acid binds to the enzyme at a different location from the active site. This is an example of ________. A) competitive inhibition B) allosteric regulation C) the specificity of enzymes for their substrates D) positive feedback regulation

allosteric regulation

One primary advantage of light microscopy over electron microscopy is that ________. A) light microscopy provides for higher magnification than electron microscopy B) light microscopy provides for higher resolution than electron microscopy C) light microscopy allows the visualization of dynamic processes in living cells D) light microscopy provides higher contrast than electron microscopy

allows VISUALIZATION of DYNAMIC PROCESSES in living cells

Elements found on the left side of the periodic table contain outer shells that are ________; these elements tend to form ________ in solution. A) almost empty; cations B) almost empty; anions C) almost full; cations D) almost full; anions

almost empty; cations

In sickle-cell disease, as a result of a single amino acid change, the mutant hemoglobin tetramers associate with each other and assemble into large fibers. Based on this information alone, we can conclude that sickle-cell hemoglobin exhibits ________. A) only altered primary structure B) only altered tertiary structure C) only altered quaternary structure D) altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered

altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered

3H2 + N2 <----------> 2NH3 51) Which of the following is true for the reaction? A) The reaction is nonreversible. B) Hydrogen and nitrogen are the reactants of the reverse reaction. C) Ammonia is being formed and decomposed simultaneously. D) Only the forward or reverse reactions can occur at one time.

ammonia is being formed and decomposed simultaneously

An obstetrician knows that one of her patients is a pregnant woman whose fetus is at risk for a serious disorder that is detectable biochemically in fetal cells. The obstetrician would most reasonably offer which of the following procedures to her patient? A) karyotyping of the woman's somatic cells B) X-ray C) amniocentesis or CVS D) blood transfusion

amniocentesis or CVS

Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because they ________. A) are species specific B) always lead to the same cellular response C) amplify the original signal many times D) counter the harmful effects of phosphatases

amplify the original signal many times

Which of the following events ACCOMPANIES ABSORPTION of energy by chlorophyll molecules of the reaction-center complex? A) ATP is synthesized from the energy absorbed. B) An electron is excited. C) NADP+ is reduced to NADPH. D) A molecule of water is split.

an ELECTRON is EXCITED

Which of the following molecules is most similar in structure to ATP? A) a pentose sugar B) a DNA nucleotide C) an RNA nucleotide D) an amino acid with three phosphate groups attached

an RNA nucleotide

Which kind of metabolic poison would most directly interfere with glycolysis? A) an agent that reacts with oxygen and depletes its concentration in the cell B) an agent that binds to pyruvate and inactivates it C) an agent that closely mimics the structure of glucose but is not metabolized D) an agent that reacts with NADH and oxidizes it to NAD+

an agent that closely mimics the structure of glucose but is not metabolized

Atoms have no electric charge because they have ________. A) uncharged neutrons in their nuclei B) an equal number of protons and neutrons C) an equal number of protons and electrons D) an equal number of charged and uncharged subatomic particles

an equal number of protons and ELECTRONS

Which of the following processes might produce a human zygote with 45 chromosomes? A) an error in meiotic anaphase occurring in either an egg or sperm B) failure of the egg nucleus to be fertilized by the sperm C) failure of an egg to complete meiosis II D) incomplete cytokinesis during spermatogenesis after meiosis I

an error in meiotic anaphase occurring in either an egg or sperm

Which of the following types of reactions would decrease the entropy within a cell? A) anabolic reactions B) hydrolysis C) digestion D) catabolic reactions

anabolic reactions

During which phase of mitosis do the CHROMATIDS s become CHROMOSOMES? A) telophase B) anaphase C) prophase D) metaphase

anaphase

During which of the following phases of meiosis do homologous chromosomes separate? A) anaphase II B) prophase I C) mitosis D) anaphase I

anaphase I

Mendel's observation of the segregation of alleles in gamete formation has its basis in which of the following phases of cell division? A) prophase I of meiosis B) anaphase II of meiosis C) metaphase II of meiosis D) anaphase I of meiosis

anaphase I of meiosis

During which of the following phases of meiosis do centromeres split and sister chromatids migrate to opposite poles of the cell? A) anaphase I B) telophase I C) anaphase II D) telophase II

anaphase II

Which of the following types of cells utilize deoxyribonucleic acid (DNA) as their genetic material but do not have their DNA encased within a nuclear envelope? A) animal B) plant C) archaean D) fungi

archaen

Research indicates that IBUPROFEN, a drug used to relieve inflammation and pain, is a mixture of two enantiomers; that is, molecules that ________. A) have identical chemical formulas but differ in the branching of their carbon skeletons B) are mirror images of each other C) differ in the location of their double bonds D) differ in the arrangement of atoms around their double bonds

are MIRROR images of each other

Cohesion, surface tension, and adhesion are the properties of water molecules that ________. A) increase when temperature increases B) increase when pH increases C) are a result of hydrogen bonding D) are a result of polar covalent bonding

are a result of hydrogen bonding

Starch and cellulose ________. A) are polymers of glucose B) are cis and trans isomers of each other C) are used for energy storage in plants and animals D) are structural components of the plant cell wall

are polymers of glucose

In comparison to eukaryotes, prokaryotes ________. A) are more structurally complex B) are larger C) are smaller D) do not have membranes

are smaller

Why are the REACTION CENTERS of photosystems composed of several structurally different pigments? A) Excited electrons must pass through several pigments before they can be transferred to electron acceptors of the electron transport chain. B) This arrangement enables the plant to absorb light energy of a variety of wavelengths. C) This arrangement enables the plant to absorb more photons from light energy, all of which are at the same wavelength. D) This arrangement enables the reaction center to excite electrons to a higher energy level.

arrangement enables the PLANT to absorb light energy of a VARIETY OF WAVELENGTHS

The figure shows the pedigree for a family. Dark-shaded symbols represent individuals with one of the two major types of colon cancer. Numbers under the symbols are the individual's age at the time of diagnosis. Males are represented by squares, females by circles. From this pedigree, this trait seems to be inherited ________. A) from mothers B) as an autosomal recessive C) as a result of epistasis D) as an autosomal dominant

as an autosomal dominant

Many G protein-coupled receptors contain seven transmembrane α-helical domains. The amino end of the protein lies at the exterior of the plasma membrane. Loops of amino acids connect the helices either at the exterior surface or on the cytosolic surface of the membrane. The loop on the cytosolic side between helices 5 and 6 is usually substantially longer than the others. Where would you expect to find the carboxyl end of the protein? A) at the exterior surface B) at the cytosolic surface C) connected with the loop at H5 and H6 D) embedded in the phospholipid bilayer of the membrane

at the cytosolic surface

Many G protein-coupled receptors contain seven transmembrane α-helical domains. The amino end of the protein lies at the exterior of the plasma membrane. Loops of amino acids connect the helices either at the exterior surface or on the cytosolic surface of the membrane. The loop on the cytosolic side between helices 5 and 6 is usually substantially longer than the others. Where would a coupled G protein most likely interact with this receptor? A) at the amino end B) at the carboxyl end C) along the exterior margin D) at the loop between H5 and H6

at the loop between H5 and H6

The left to right order of elements in the periodic table is based on their ________. A) atomic mass B) atomic number C) electric charge of the atom D) the number of neutrons

atomic number

Which of the following properties is associated with a CYCLIN DEPENDENT KINASE (Cdk)? A) A Cdk is inactive, or "turned off," in the presence of a cyclin. B) The number of Cdk molecules increases during the S and G2 phases and decrease during M. C) A Cdk is an enzyme that catalyzes the attachment of kinetochores to microtubules. D) A Cdk is an enzyme that attaches phosphate groups to other proteins.

attaches to PHOSPHATE GROUPS to other PROTEINS

Which of the following statements correctly describes a distinction between AUTOTROPH AND HETEROTROPHS? A) Cellular respiration is unique to heterotrophs. B) Only heterotrophs have mitochondria. C) Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic. D) Only heterotrophs require oxygen.

autotrophs, but not heterotrophs can nourish themselves beginning with CO2 and other NUTRIENTS that are ORGANIC

The figure illustrates the energy states associated with the reaction A + B ↔ C + D. Which of the following represents the activation energy required for the enzyme-catalyzed reaction in the figure? A) a B) b C) c D) d

Use the following information to answer the question. In a series of mapping experiments, the recombination frequencies for four different linked genes of Drosophila were determined as shown in the figure. Based on this information, what is the order of these genes on a chromosome map? A) rb-cn-vg-b B) cn-rb-b-vg C) b-rb-cn-vg D) vg-cn-b-rb

b-rb-cn-vg

Theodor W. Engelmann illuminated a filament of algae with light that passed through a PRISM, thus exposing different segments of algae to different wavelengths of light. He added AEROBI BACTERIA and then noted in which areas the bacteria congregated. He noted that the largest groups were found in the areas illuminated by the red and blue light. What did ENGLEMANN conclude about the congregation of bacteria in the red and blue areas? A) Bacteria congregated in these areas due to an increase in the temperature of the red and blue light. B) Bacteria congregated in these areas because these areas had the most oxygen being released. C) Bacteria are attracted to red and blue light and thus these wavelengths are more reactive than other wavelengths. D) Bacteria congregated in these areas due to an increase in the temperature caused by an increase in photosynthesis.

bacteria congregated in these areas because these areas had the MOST OXYGEN RELEASED

A FLASK containing photosynthetic GREEN ALGAE and a control flask containing water with no algae are both placed under a bank of lights that is set to cycle between 12 hours of light and 12 hours of dark. The dissolved oxygen concentrations in both flasks are monitored. Predict what the relative dissolved oxygen concentrations will be in the flask with algae compared to the control flask. The dissolved oxygen in the flask with algae will ________. A) always be higher B) always be lower C) be higher in the light, but the same in the dark D) be higher in the light, but lower in the dark

be HIGHER in the light, but LOWER in the DARK

Compared to a hydrocarbon chain where all the carbon atoms are linked by single bonds, a HYDROCARBON CHAIN with the same number of carbon atoms but with one or more double bonds will ________. A) be more flexible in structure B) be more constrained in structure C) be more polar D) have more hydrogen atoms

be more CONSTRAINED

Which of the following statements describes an example of cooperativity associated with enzyme regulation? A) binding of the end product of a metabolic pathway to the first enzyme in the pathway to inhibit the enzyme B) one enzyme in a metabolic pathway passing its product to act as a substrate for the next enzyme in the pathway C) binding a substrate to one subunit of a tetramer stimulates faster binding of substrate to each of the other three subunits D) binding of an ATP molecule along with another substrate molecule in the active site of the

binding a substrate to one subunit of a tetramer stimulates faster binding of substrate to each of the other three subunits

ACCURACY in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the ________. A) binding of ribosomes to mRNA B) binding of the anticodon to small subunit of the ribosome C) attachment of amino acids to rRNAs D) binding of the anticodon to the codon and the attachment of amino acids to tRNAs

binding of the ANTICODON to the CODON and the attachment of amino acids to tRNAs

If a pharmaceutical company wished to design a drug to maintain low blood sugar levels, one approach might be to design a compound that does which of the following? A) activates epinephrine receptors in liver cells B) increases cAMP production in liver cells C) blocks G protein activity in liver cells D) increases glycogen phosphorylase activity in liver cells

blocks G protein activity in liver cells

Feather color in budgies is determined by two different genes: Y for pigment on the outside of the feather, and B for pigment on the inside of the feather. YYBB, YyBB, or YYBb is green; yyBB or yyBb is blue; YYbb or Yybb is yellow; and yybb is white. A blue budgie is crossed with a white budgie. Which of the following results in the offspring is most possible? A) green offspring only B) white offspring only C) blue offspring only D) blue and white offspring

blue and white offspring

In which reactions of cellular respiration and fermentation does SUBSTRATE LEVEL PHOSPOHRLATION occur? A) only in glycolysis B) only in the citric acid cycle C) only in the electron transport chain D) in both glycolysis and the citric acid cycle

both GLYCOlYSIS and CITRIC ACID cycle

How does 0.5 M sucrose (molecular mass 342) solution compare to 0.5 M glucose (molecular mass 180) solution? A) Both have 6.02 × 1023 molecules. B) Sucrose has 171 molecules, whereas glucose has 90. C) Both have 3.01 × 1023 molecules. D) Sucrose has 171 mg/L, whereas glucose has 90 mg/L.

both have 3.01x10^23 molecules

Which of the following could be responsible for atherosclerosis and should be eliminated from diet for health reasons? A) butter B) olive oil C) liver and kidney organ meat D) butter, liver, and kidney organ meat

butter, liver, and kidney organ meat

How does a noncompetitive inhibitor decrease the rate of an enzyme-catalyzed reaction? A) by binding to the active site of the enzyme, thus preventing binding of the normal substrate B) by binding to an allosteric site, thus changing the shape of the active site of the enzyme C) by decreasing the free-energy change of the reaction catalyzed by the enzyme D) by binding to the substrate, thus changing its shape so that it no longer binds to the active site of the enzyme

by binding to an allosteric site, thus changing the shape of the active site of the enzyme

Many organisms spend most of their life cycle in the diploid state. If meiosis produces haploid cells, how is the diploid number restored for these types of organisms? A) by DNA replication B) through the transcription of DNA to RNA C) by synapsis of the homologous pairs of chromosomes during prophase of meiosis I D) by fertilization

by fertilization

In an HIV-infected cell producing HIV virus particles, the viral glycoprotein is expressed on the plasma membrane. How do the viral glycoproteins get to the plasma membrane? They are synthesized ________. A) on ribosomes on the plasma membrane B) by ribosomes in the rough ER and arrive at the plasma membrane in the membrane of secretory vesicles C) on free cytoplasmic ribosomes and then inserted into the plasma membrane D) by ribosomes in the rough ER, secreted from the cell, and inserted into the plasma membrane from the outside

by ribosomes in the rough ER and arrive at the plasma membrane in the membrane of secretory vesicles

The figure illustrates the energy states associated with the reaction A + B ↔ C + D. Which of the following represents the activation energy required for the non-enzyme-catalyzed reaction in the figure? A) a B) b C) c D) d

Which line in the graph represents the bag that contained a solution isotonic to the 0.6 M solution at the beginning of the experiment? A) A B) B C) C D) D

Caffeine is an inhibitor of phosphodiesterase. Therefore, the cells of a person who has recently consumed coffee would have increased levels of which of the following molecules? A) phosphorylated proteins B) cAMP C) adenylyl cyclase D) activated G proteins

cAMP

Consider this pathway: epinephrine → G protein-coupled receptor → G protein → adenylyl cyclase → cAMP The second messenger in this pathway is ________. A) cAMP B) G protein C) adenylyl cyclase D) G protein-coupled receptor

cAMP

Consider this pathway: epinephrine → G protein-coupled receptor → G protein → adenylyl cyclasec → AMP. Identify the second messenger. A) cAMP B) G protein C) GTP D) adenylyl cyclase

cAMP

Which of the following is true of CARBON? A) It forms only polar molecules. B) It can form a maximum of three covalent bonds with other elements. C) It is highly electronegative. D) It can form both polar and nonpolar bonds.

can form both POLAR and NONPOLAR bonds

According to the fluid MOSAIC MODEL of cell membranes, phospholipids ________. A) can move laterally along the plane of the membrane B) frequently flip-flop from one side of the membrane to the other C) occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane D) have hydrophilic tails in the interior of the membrane

can move LATERALLY along the PLANE of the membrane

The element present in all organic molecules is ________. A) hydrogen B) oxygen C) carbon D) nitrogen

carbon

About 25 of the 92 natural elements are known to be essential to life. Which 4 of these 25 elements make up approximately 96% of living matter? A) carbon, sodium, hydrogen, nitrogen B) carbon, oxygen, phosphorus, hydrogen C) oxygen, hydrogen, calcium, nitrogen D) carbon, hydrogen, nitrogen, oxygen

carbon, hydrogen, nitrogen, oxygen

Amino acids are acids because they ALWAYS POSESS________ as the functional group? A) amino B) carbonyl C) carboxyl D) phosphate

carboxyl

Which parts of the amino acids X and Y are involved in the formation of a peptide bond? X—Y A) amino group of X and carboxyl group of Y B) carboxyl group of X and amino group of Y C) carboxyl group of X and side chain of Y D) side chains of both X and Y

carboxyl group of X and amino group of Y

Certain cell types normally have several nuclei per cell. How could such MULTINUCLEATED cells be explained? A) The cell underwent repeated cytokinesis but no mitosis. B) The cell underwent repeated mitosis with simultaneous cytokinesis. C) The cell underwent repeated mitosis, but cytokinesis did not occur. D) The cell had multiple S phases before it entered mitosis.

cell underwent repeated MITOSIS but NO CYTOKINESIS

Which of the following effects might be caused by reduced or very LITTLE ACTIVE TELOMERASE activity? A) Cells may become cancerous. B) Telomere lengthens in germ cells. C) Cells age and begin to lose function. D) Cells maintain normal functioning.

cells AGE and begin to lose function

Early observations of a cultured cell line indicated that the cells did not exhibit either density-dependent inhibition or anchorage dependence. What do these observations suggest about this cell line? A) The cells are unable to form spindle microtubules. B) The cells follow an altered series of cell cycle phases. C) The cells show characteristics of tumors. D) The cells have nonfunctional MPF.

cells show characteristics of tumors

In the cells of some organisms, mitosis occurs without cytokinesis. This will result in A) cells with more than one nucleus. B) cells that are unusually small. C) cells lacking nuclei. D) cell cycles lacking an S phase.

cells with more than one nucleus.

Which organelle often takes up much of the volume of a plant cell? A) lysosome B) central vacuole C) Golgi apparatus D) chloroplast

central vacuole

Cells are ________. A) only found in pairs, because single cells cannot exist independently B) limited in size to 200 and 500 micrometers in diameter C) characteristic of eukaryotic but not prokaryotic organisms D) characteristic of prokaryotic and eukaryotic organisms

characteristic of prokaryotic and eukaryotic organisms

Which structure below is independent of the endomembrane system? A) nuclear envelope B) chloroplast C) Golgi apparatus D) plasma membrane

chloroplast

Which structure is not part of the endomembrane system? A) nuclear envelope B) chloroplast C) Golgi apparatus D) plasma membrane

chloroplast

Which of the following types of molecules LACK HYDROPHILIC DOMAINS? A) transmembrane proteins B) integral membrane proteins C) peripheral membrane proteins D) cholesterol

cholesterol

Certain unicellular eukaryotes, including DIATOMS and some YEASTS, have mechanisms of nuclear division that may resemble intermediate steps in the evolution of mitosis. Which of the following is a characteristic feature of NUCLEAR DIVISION in these organisms? A) They reproduce by binary fission in their early stages of development and by mitosis when they are mature. B) They have circular chromosomes that are segregated by a mitotic spindle. C) Chromosomes are segregated by a mitotic spindle, but the nuclear envelope remains intact during division. D) Chromosomes are segregated by attachment to the plasma membrane.

chromosomes are separated by MITOTIC SPINDLE but the nuclear envelope remains in tact during division

Use the following figure to answer the question. (web like) The two molecules shown in the figure are best described as ________. A) enantiomers B) radioactive isotopes C) structural isomers D) cis-trans isomers

cis-trans isomers

Most CO2 from catabolism is released during A) glycolysis. B) the citric acid cycle. C) lactate fermentation. D) electron transport.

citric acid cycle.

HIV is the virus that causes AIDS. In the mid-1990s, researchers discovered an enzyme in HIV called protease. Once the enzyme's structure was known, researchers began looking for drugs that would fit into the active site and block it. If this strategy for stopping HIV infections were successful, it would be an example of what phenomenon? A) noncompetitive inhibition B) denaturation C) allosteric regulation D) competitive inhibition

competitive inhibition

Which of the following conditions may be overcome by increasing the substrate concentration in an enzymatic reaction with a fixed amount of enzyme? A) the need for a coenzyme B) allosteric inhibition C) noncompetitive inhibition D) competitive inhibition

competitive inhibition

The ANTICODON OF A PARTICULAR tRNA molecule is A) complementary to the corresponding mRNA codon. B) complementary to the corresponding triplet in rRNA. C) the part of tRNA that bonds to a specific amino acid. D) catalytic, making the tRNA a ribozyme.

complementary to the corresponding (mRNA) codon

Water molecules can form hydrogen bonds with ________. A) compounds that have polar covalent bonds B) oils C) oxygen gas (O2) molecules D) chloride ions

compounds that have POLAR covalent bonds

A signal transmitted via phosphorylation of a series of proteins is generally associated with which of the following events? A) conformational changes to each protein in the series B) binding of a hormone to an intracellular receptor C) activation of a ligand-gated ion channel D) production of ATP in the process of signal transduction

conformational changes to each protein in the series

Which of the following statements is true of METABOLISM IN ITS ENTIREITY in all organisms? A) Metabolism depends on a constant supply of energy from food. B) Metabolism uses all of an organism's resources. C) Metabolism consists of all the energy transformation reactions in an organism. D) Metabolism manages the increase of entropy in an organism.

consists of ALL ENERGY TRANSFORMATION REACTIONS in an organism

Saturated fats ________. A) are more common in plants than in animals B) have multiple double bonds in the carbon chains of their fatty acids C) are generally liquid at room temperature D) contain more hydrogen than unsaturated fats that consist of the same number of carbon atoms

contain more hydrogen than unsaturated fats that consist of the same number of carbon atoms

One difference between cancer cells and normal cells is that cancer cells A) are unable to synthesize DNA. B) are arrested at the S phase of the cell cycle. C) continue to divide even when they are tightly packed together. D) cannot function properly because they are affected by density-dependent inhibition.

continue to divide even when they are tightly packed together.

The phosphate transport system in bacteria imports phosphate into the cell even when the concentration of phosphate outside the cell is much lower than the cytoplasmic phosphate concentration. Phosphate import depends on a pH gradient across the membrane—more acidic outside the cell than inside the cell. In this bacterial cell, phosphate transport is an example of ________. A) passive diffusion B) facilitated diffusion C) active transport D) cotransport

cotransport

In some cells, there are many ion electrochemical gradients across the plasma membrane even though there are usually only one or two proton pumps present in the membrane. The gradients of the other ions are most likely accounted for by ________. A) cotransport proteins B) ion channels C) pores in the plasma membrane D) passive diffusion across the plasma membrane

cotransport proteins

The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient, is an example of which of the following processes? A) active transport B) allosteric regulation C) a reaction with a positive ΔG D) coupling of an endergonic reaction to an exergonic reaction

coupling of an endergonic reaction to an exergonic reaction

A carbon atom is most likely to form what kind of bond(s) with other atoms? A) ionic B) hydrogen C) covalent D) ionic bonds, covalent bonds, and hydrogen bonds

covalent

Which bond or interaction would be difficult to disrupt when compounds are put into water? A) covalent bonds between carbon atoms B) hydrogen bonds C) ionic bonds D) ionic and hydrogen bonds

covalent bonds between carbon atoms

The bulldog ant has a diploid number of two chromosomes. Therefore, following meiosis, each daughter cell will have a single chromosome. In addition to mutations, how might genetic diversity be generated in this species? A) crossing over only B) independent assortment only C) crossing over and random fertilization D) nothing else

crossing over and random fertilization

What two components constitute an active MPF? A) a growth factor and mitotic factor B) ATP synthetase and a protease C) cyclin and tubulin D) cyclin and a cyclin-dependent kinase

cyclin and a cyclin dependent KINASE

The figure illustrates the energy states associated with the reaction A + B ↔ C + D. Which of the following in the figure would be the same in either an enzyme-catalyzed or a noncatalyzed reaction? A) a B) b C) c D) d

Based on Figure 7.18, which of these experimental treatments would increase the rate of sucrose transport into a plant cell? A) decreasing extracellular sucrose concentration B) decreasing extracellular pH C) decreasing cytoplasmic pH D) adding a substance that makes the membrane more permeable

decreasing extracellular pH

Which of the following best summarizes the relationship between DEHYDRATION REACTIONS AND HYDROLYSIS A) Dehydration reactions assemble polymers; hydrolysis reactions break polymers apart. B) Dehydration reactions eliminate water from membranes; hydrolysis reactions add water to membranes. C) Dehydration reactions and hydrolysis reactions assemble polymers from monomers. D) Hydrolysis reactions create polymers, and dehydration reactions create monomers.

dehydration reaction ASSEMBLE POLYMERS; hydrolysis reactions BREAK

The ELONGATION OF THE LEADING strand during DNA synthesis A) progresses away from the replication fork. B) occurs in the 3′ → 5′ direction. C) produces Okazaki fragments. D) depends on the action of DNA polymerase.

depends on the ACTION OF THE DNA POLYMERASE

Cotton-topped tamarins are small primates with tufts of long white hair on their heads. While studying these creatures, you notice that males with longer hair get more opportunities to mate and father more offspring. To test the hypothesis that having longer hair is adaptive in these males, you should ________. A) test whether other traits in these males are also adaptive B) look for evidence of hair in ancestors of tamarins C) determine if hair length is heritable D) test whether males with shaved heads are still able to mate

determine if hair length is heritable

Which one of the following is not a plausible hypothesis that can be tested in this experiment? A) The longer day lengths of summer trigger the development of twig-like caterpillars. B) The cooler temperatures of spring trigger the development of flowerlike caterpillars. C) Differences in air pressure, due to differences in elevation, trigger the development of different types of caterpillars. D) Differences in diet trigger the development of different types of caterpillars.

differences in air pressure, due to differences in elevation, trigger the development of different types of caterpillars

The individual with genotype AaBbCCDdEE can make many kinds of gametes. Which of the following correctly describes why this situation is possible? A) recurrent mutations form new alleles B) crossing over during prophase I leads to genetic variety C) different possible assortment of chromosomes into gametes occurs D) there is a tendency for dominant alleles to segregate together

different possible assortment of chromosomes into gametes occurs

The activation of receptor tyrosine kinases is characterized by A) dimerization and phosphorylation. B) dimerization and IP3 binding. C) a phosphorylation cascade. D) GTP hydrolysis.

dimerization and phosphorylation.

Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of microtubules, its effectiveness must be related to A) disruption of mitotic spindle formation. B) suppression of cyclin production. C) myosin denaturation and inhibition of cleavage furrow formation. D) inhibition of DNA synthesis.

disruption of mitotic spindle formation.

Cooking oil and gasoline (a hydrocarbon) are not amphipathic molecules because they ________. A) do not have a polar or charged region B) do not have a nonpolar region C) have hydrophobic and hydrophilic regions D) are highly reduced molecules

do not have a polar or charged regio

A neutral atom has two, eight, eight electrons in its first, second, and third energy levels. This information ________. A) does not tell us about the atomic number of the element B) does not tell us about the chemical properties of the element C) does not tell us about the atomic mass of the element D) does not tell us about the size of the element

does not tell us about the ATOMIC MASS

For the enzyme-catalyzed reaction shown in the figure, if the initial reactant concentration is 1.0 micromolar, which of these treatments will cause the greatest increase in the rate of the reaction? A) doubling the activation energy needed B) cooling the reaction by 10°C C) doubling the enzyme concentration D) increasing the concentration of reactants to 10.0 micromolar, while reducing the concentration of enzyme by 1/2

doubling the enzyme concentration

During which of the following processes do sister chromatids separate from each other? A) during meiosis I only B) during meiosis II only C) during both mitosis and meiosis I D) during both mitosis and meiosis II

during both mitosis and meiosis II

Nitrogen (N) is more electronegative than hydrogen (H). Which of the following is a correct statement about the atoms in ammonia (NH3)? A) Each hydrogen atom has a partial positive charge; the nitrogen atom has a partial negative charge. B) Ammonia has an overall positive charge. C) Ammonia has an overall negative charge. D) The nitrogen atom has a partial positive charge; each hydrogen atom has a partial negative charge.

each HYDROGEN atom has a PARTIAL POSITIVE charge; the nitrogen atom has a partial negative charge

A(n) ________ has charge but negligible mass, whereas a(n) ________ has mass but no charge. A) proton; neutron B) neutron; proton C) neutron; electron D) electron; neutron

electron, neutron

Van der Waals interactions may result when ________. A) electrons are not symmetrically distributed in a molecule B) molecules held by ionic bonds react with water C) two polar covalent bonds react D) a hydrogen atom loses an electron

electrons are not symmetrically distributed in a molecule

According to the fluid mosaic model of membrane structure, proteins of the membrane are mostly A) spread in a continuous layer over the inner and outer surfaces of the membrane. B) confined to the hydrophobic interior of the membrane. C) embedded in a lipid bilayer. D) randomly oriented in the membrane, with no fixed inside-outside polarity.

embedded in a lipid bilayer.

A chemical reaction that has a positive ΔG is best described as ________. A) endergonic B) enthalpic C) spontaneous D) exergonic

endergonic

The evolution of eukaryotic cells most likely involved ________. A) endosymbiosis of an oxygen-using bacterium in a larger bacterial host cell-the endosymbiont evolved into chloroplasts B) endosymbiosis of a photosynthetic archaeal cell in a larger bacterial host cell to escape toxic oxygen—the anaerobic archaea evolved into chloroplasts C) endosymbiosis of an oxygen-using bacterium in a larger bacterial host cell-the endosymbiont evolved into mitochondria D) evolution of an endomembrane system and subsequent evolution of mitochondria from a portion of the smooth endoplasmic reticulum

endosymbiosis of an oxygen-using bacterium in a larger bacterial host cell-the endosymbiont evolved into mitochondria

In chemiosmosis, what is the most direct source of energy that is used to convert ADP + i to ATP? A) energy released as electrons flow through the electron transport chain B) energy released from substrate-level phosphorylation C) energy released from movement of protons through ATP synthase, down their electrochemical gradient D) energy released as electrons are transported across the inner mitochondrial membrane

energy released from movement of protons through ATP synthase, down their electrochemical gradient

What would you expect to happen if MPF (maturation-promoting factor) is introduced into immature FROG OOCYTES that are arrested in G2? A) The cells would remain arrested in G2. B) The cells would enter G0. C) The cells would enter mitosis. D) The cells would begin DNA synthesis.

enter MITOSIS

Fatty acids usually have an even number of carbons in their structures. Catabolism of fatty acids produces two-carbon fragments that are converted to acetyl CoA molecules. What is the most likely way in which these acetyl CoA molecules would be metabolized in aerobic cellular respiration? A) They would directly enter the electron transport chain. B) They would directly enter the energy-yielding phase of glycolysis. C) They would be converted to pyruvate and then undergo pyruvate oxidation upon transport into mitochondria. D) They would directly enter the citric acid cycle.

enter the citric acid cycle.

Why do neurons and some other specialized cells DIVIDE INFREQUENTLY? A) They no longer have active nuclei. B) They have entered into G0. C) They can no longer degrade cyclins. D) They no longer produce MPF.

entered into G0

Hydrangea plants of the same genotype are planted in a large flower garden. Some of the plants produce blue flowers and others pink flowers. This can be best explained by which of the following? A) the knowledge that multiple alleles are involved B) the allele for blue hydrangea is completely dominant over the allele for pink hydrangea C) the alleles are codominant D) environmental factors such as soil pH affect the phenotype

environmental factors such as soil pH affect the phenotype

Gene S controls the sharpness of spines in a type of cactus. Cacti with the dominant allele, S, have sharp spines, whereas homozygous recessive ss cacti have dull spines. At the same time, a second gene, N, determines whether or not cacti have spines. Homozygous recessive nn cacti have no spines at all. The relationship between genes S and N is an example of which of the following inheritance patterns? A) incomplete dominance B) epistasis C) pleiotropy D) codominance

epistasis

A characteristic 9 + 2 arrangement of microtubules, consisting of nine doublets of microtubules surrounding a pair of single microtubules is associated with ________. A) bacterial flagella B) eukaryotic flagella and motile cilia C) eukaryotic flagella, motile cilia, and nonmotile cilia D) centrioles and basal bodies

eukaryotic flagella and motile cilia

The figure illustrates the energy states associated with the reaction A + B ↔ C + D. Which of the following terms best describes the forward reaction in the figure? A) endergonic, ∆G > 0 B) exergonic, ∆G < 0 C) endergonic, ∆G < 0 D) exergonic, ∆G > 0

exergonic, ∆G < 0

Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as ________ is to ________. A) exergonic; spontaneous B) exergonic; endergonic C) free energy; entropy D) work; energy

exergonic; endergonic

The relationship between catabolism and anabolism is most similar to the relationship between which of the following pairs of terms? A) exergonic; spontaneous B) exergonic; endergonic C) free energy; entropy D) work; free energy

exergonic; endergonic

Abnormal chromosomes are frequently found in malignant tumors. Errors such as translocations may place a gene in close proximity to different control regions. Which of the following events might then occur to make the cancer worse? A) an increase in nondisjunction B) expression of inappropriate gene products C) a decrease in mitotic frequency D) failure of the cancer cells to multiply

expression of inappropriate gene products

________ is a regulatory mechanism in which the end product of a metabolic pathway inhibits an enzyme that catalyzes an early step in the pathway. A) Allosteric inhibition B) Cooperative inhibition C) Feedback inhibition D) Metabolic inhibition

feedback inhibition

Organic molecules with ONLY HYDROGENS AND 5 CARBONS CANNOT ________. A) have a branching carbon skeleton B) have different combinations of double bonds between carbon atoms C) have different positions of double bonds between carbon atoms D) form enantiomers

form ENANTIOMERS

Which of the following correctly describes chemical equilibrium? A) Forward and reverse reactions continue with no net effect on the concentrations of the reactants and products. B) Concentrations of products are higher than the concentrations of the reactants. C) There are equal concentrations of products and reactants while forward and reverse reactions continue. D) There are equal concentrations of reactants and products, and the reactions have stopped.

forward and reverse reactions continue with no net effect on the concentrations of the reactants and products

Which of the following processes occurs in a plant's sexual life cycle? A) sporophytes produce gametes by meiosis B) gametophytes produce gametes by mitosis C) gametophytes produce gametes by meiosis D) sporophytes produce gametes by mitosis

gametophytes produce gametes by mitosis

Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an adjacent cell through ________. A) plasmodesmata B) tight junctions C) desmosomes D) gap junctions

gap junctions

Which of the following characteristics of eukaryotic telomeres cause them to replicate differently than the rest of the chromosome? A) the activity of telomerase enzyme B) DNA polymerase that cannot replicate the leading strand template to its 5'end C) gaps left at the 5' end of the lagging strand template D) gaps left at the 3' end of the lagging strand because of the need for a primer

gaps left at the 5' end of the lagging strand template

The process by which the information in a gene directs the synthesis of a protein is called ________. A) gene expression B) replication C) post translation modification D) cloning

gene expression

Mitochondrial DNA is primarily involved in coding for proteins needed for protein complexes of the electron transport chain and ATP synthase. Therefore, mutations in mitochondrial genes would most affect which of the following processes? A) DNA synthesis in cells of the immune system B) the movement of oxygen into erythrocytes C) generation of ATP in muscle cells D) the storage of urine in the urinary bladder

generation of ATP in muscle cells

Which of the following is NOT A POLYMER? A) glucose B) starch C) RNA D) DNA

glucose

Which of the following sequences describes the path by which electrons travel downhill energetically in aerobic respiration? A) glucose → NADH → electron transport chain → oxygen B) glucose → pyruvate → ATP → oxygen C) glucose → pyruvate → electron transport chain → NADH → ATP D) food → glycolysis → citric acid cycle → NADH → ATP

glucose → NADH → electron transport chain → oxygen

In plant cells, the middle lamella ________. A) glues adjacent cells together B) prevents dehydration of adjacent cells C) connects the cytoplasm of adjacent cells D) prevents excessive uptake of water by plant cells

glues adjacent cells together

Which observation suggested to SUTHERLAND the involvement of a second messenger in EPIINEPHRINE's effect on liver cells? A) Receptor studies indicated that epinephrine was a ligand. B) Glycogen breakdown was observed only when epinephrine was administered to intact cells. C) Glycogen breakdown was observed when epinephrine and glycogen phosphorylase were combined in a cell-free system. D) Epinephrine was known to have different effects on many types of cells.

glycogen breakdown was observed only when ep administered to INTACT CELLS

Which metabolic pathway is common to both fermentation and cellular respiration of a glucose molecule? A) the citric acid cycle B) the electron transport chain C) glycolysis D) reduction of pyruvate to lactate

glycolysis

Which of the following metabolic processes normally occurs regardless of whether or not oxygen (O2) is present? A) citric acid cycle B) glycolysis C) lactate fermentation D) oxidative phosphorylation

glycolysis

Which of the following metabolic processes take place in the cytosol of a eukaryotic cell? A) glycolysis and fermentation B) fermentation and chemiosmosis C) oxidation of pyruvate to acetyl CoA D) citric acid cycle

glycolysis and fermentation

Carbon dioxide (CO2) is readily soluble in water, according to the equation CO2 + H2O ↔ H2CO3. Carbonic acid (H2CO3) is a weak acid. If CO2 is bubbled into a beaker containing pure, freshly distilled water, which of the following graphs correctly describes the results?

graph with slight decrease

In Drosophila melanogaster, vestigial wings are determined by a recessive allele of a gene that is linked to a gene with a recessive allele that determines black body color. T. H. Morgan crossed black-bodied, normal-winged females and gray-bodied, vestigial-winged males. The F1 were all gray bodied, normal winged. The F1 females were crossed to homozygous recessive males to produce testcross progeny. Morgan calculated the map distance to be 17 map units. Which of the following information is correct about the testcross progeny? A) black-bodied, normal-winged flies = 17% of the total B) black-bodied, normal-winged flies plus gray-bodied, vestigial-winged flies = 17% of the total C) gray-bodied, normal-winged flies plus black-bodied, vestigial-winged flies = 17% of the total D) black-bodied, vestigial-winged flies = 17% of the total

gray-bodied, normal-winged flies plus black-bodied, vestigial-winged flies = 17% of the total

A cleavage furrow is ________. A) a ring of vesicles forming a cell plate B) the separation of divided prokaryotes C) a groove in the plasma membrane between daughter nuclei D) the space that is created between two chromatids during anaphase

groove

Amoebae move by crawling over a surface (cell crawling), which involves ________. A) growth of actin filaments to form bulges in the plasma membrane B) assembly of microtubule extensions that vesicles can follow in the direction of movement C) reinforcement of the pseudopod with intermediate filaments D) localized contractions driven by myosin and microtubules

growth of actin filaments to form bulges in the plasma membrane

A man who is a dwarf with achondroplasia and normal vision marries a color-blind woman of normal height. The man's father was six feet tall, and both the woman's parents were of average height. Dwarfism caused by achondroplasia is autosomal dominant, and red-green color blindness is X-linked recessive. What proportion of their sons would be color blind and of normal height? A) none B) half C) one out of four D) all

half

Liquid water ________. A) is less dense than ice B) has a specific heat lower than that of most other substances C) has a heat of vaporization higher than that of most other substances D) is nonpolar

has a heat of vaporization higher than that of most other substances

A carbon atom has 6 electrons however, its VALENCY is 4. This is because the CARBON atom ________. A) donates its 2 electrons to another atom B) shares its 2 electrons and bonds with another atom C) has 4 electrons in its first shell and 2 in the second shell D) has only 2 electrons in its first shell and 4 in the second shell

has only 2 electrons in first shell and 4 in the second

Phospholipids and triglycerides both ________. A) contain serine or some other organic compound B) have three fatty acids C) have a glycerol backbone D) have a phosphate

have a glycerol backbone

Testosterone and estradiol are male and female sex hormones, respectively, in many vertebrates. In what way(s) do these molecules differ from each other? Testosterone and estradiol ________. A) are structural isomers but have the same molecular formula B) are cis-trans isomers but have the same molecular formula C) have different functional groups attached to the same carbon skeleton D) are enantiomers of the same organic molecule

have different FUNCtIONAL groups attached to the same CARBON SKELETON

Which of the following statements about the 5 end of a polynucleotide strand of RNA is correct? A) The 5 end has a hydroxyl group attached to the number 5 carbon of ribose. B) The 5 end has a phosphate group attached to the number 5 carbon of ribose. C) The 5 end has phosphate attached to the number 5 carbon of the nitrogenous base. D) The 5 end has a carboxyl group attached to the number 5 carbon of ribose.

he 5 end has a phosphate group attached to the number 5 carbon of ribose.

A woman is found to have 47 chromosomes, including three X chromosomes. Which of the following statements describes her expected phenotype? A) a female with masculine characteristics such as facial hair B) an apparent male who is sterile C) healthy female of slightly above-average height D) a sterile female

healthy female of slightly above-average height

Which of the following statements correctly describes the STRUCTURE OF CHROMATIN A) Heterochromatin is composed of DNA, whereas euchromatin is made of DNA and RNA. B) Both heterochromatin and euchromatin are found in the cytoplasm. C) Heterochromatin is highly condensed, whereas euchromatin is less compact. D) Euchromatin is not transcribed, whereas heterochromatin is transcribed.

heterochromatin is HIGHLY CONDENSED, whereas euchromatin is less compact

Thermal energy of the water in a bathtub is ________ than in a freshly brewed coffee pot because of its ________. A) higher; greater volume B) higher; high kinetic energy C) lower; low temperature D) lower; low density

higher; greater volume

Which of the following statements accurately describes one characteristic of HISTONES? A) Each nucleosome consists of two molecules of histone H1. B) Histone H1 is not present in the nucleosome bead; instead, it draws the nucleosomes together. C) The carboxyl end of each histone extends outward from the nucleosome and is called a "histone tail." D) Histones are found in mammals, but not in other animals or in plants or fungi.

histone H1 is not present in the nucleosome BEAD; instead it draws the nucleosomes together

Which of the following structural characteristics is most critical for the ASSOCIATIONS BETWEEN HISTONES AND DNA? A) Histones are small proteins. B) Histones are highly conserved (that is, histones are very similar in every eukaryote). C) There are at least five different histone proteins in every eukaryote. D) Histones are positively charged.

histones are POSITIVELY CHARGED

Which of the following molecular characteristics cause HISTONES TO BIND TIGHTLY to DNA? A) Histones are positively charged, and DNA is negatively charged. B) Histones are negatively charged, and DNA is positively charged. C) Both histones and DNA are strongly hydrophobic. D) Histones are covalently linked to the DNA.

histones are POSITIVELY charged, and DNA is NEGATIVELY CHARGED

Humans can digest starch but not cellulose because ________. A) humans have enzymes that can hydrolyze the α-glycosidic linkages of starch but not the β- glycosidic linkages of cellulose B) starch monomers are joined by covalent bonds, and cellulose monomers are joined by ionic bonds C) the monomer of starch is glucose, while the monomer of cellulose is galactose D) Starch is softer than cellulose

humans have enzymes that can hydrolyze the α-glycosidic linkages of starch but NOT the β- glycosidic linkages of cellulose

Several epidemic microbial diseases of earlier centuries incurred high death rates because they resulted in severe dehydration due to vomiting and diarrhea. Today they are usually not fatal because we have developed which of the following types of treatments? A) antiviral medications that are efficient and work well with most viruses B) intravenous feeding techniques C) medications to slow blood loss D) hydrating drinks with high concentrations of salt and glucose

hydrating drinks with high concentrations of salt and glucose

Which of the following is broken when water evaporates? A) nonpolar covalent bonds B) ionic bonds C) hydrogen bonds D) polar covalent bonds

hydrogen bonds

In a liver cell detoxifying alcohol and some other poisons, the enzymes of the peroxisome remove hydrogen from these molecules and ________. A) combine the hydrogen with water molecules to generate hydrogen peroxide B) combine the hydrogen with oxygen molecules to generate hydrogen peroxide C) combine the hydrogen with hydrogen peroxide to generate oxygen D) combine the hydrogen with hydrogen peroxide to generate oxygen and water

hydrogen with oxygen molecules to generate hydrogen peroxide

Viagra causes dilation of blood vessels and increased blood flow to the penis, facilitating erection. Viagra acts by inhibiting which of the following events? A) hydrolysis of cGMP to GMP B) hydrolysis of GTP to GDP C) dephosphorylation of cGMP D) formation of cGMP from GTP

hydrolysis of cGMP to GMP

During which of the following processes does independent assortment of chromosomes occur? A) in meiosis I only B) in meiosis II only C) in mitosis and meiosis I D) in mitosis and meiosis II

in meiosis I only

Where are proteins produced other than on ribosomes free in the cytosol or ribosomes attached to the endoplasmic reticulum? A) in lysosomes B) in the Golgi apparatus C) in the nucleolus D) in mitochondria

in mitochondria

Scientists isolate cells in various phases of the cell cycle. They isolate a group of cells that have 1 1/2 times more DNA than G1 phase cells. What is the most likely part of the cell cycle from which these cells were isolated? A) between the G1 and S phases in the cell cycle B) in the G2 phase of the cell cycle C) in the M phase of the cell cycle D) in the S phase of the cell cycle

in the S PHASE of the cell cycle

If plant cells are grown on media containing radioactively labeled thymine for one generation, radioactively labeled macromolecules will be detected in which of the following? A) only in the nucleus B) only in the nucleus and mitochondria C) only in the nucleus and chloroplasts D) in the nucleus, mitochondria, and chloroplasts

in the nucleus, mitochondria, and chloroplasts

35) The best experimental design ________. A) includes a large sample size for each condition B) includes a control C) alters only one condition between the controls and the experimental condition D) includes a large sample size and a control, and alters only one condition between the controls and the experimental condition

includes a large sample size and a control, and alters only one condition between the controls and the experimental condition

Use the following figure to answer the question. The phylogenetic tree ________. A) depicts that Archaea is closer to Bacteria than Eukarya B) depicts that Eukarya is closer to Bacteria than Archaea C) includes unicellular and some forms of multicellular life, but not complex animals and plants D) includes every single life form on this earth

includes every single life form on this earth

Radish flowers may be red, purple, or white. A cross between a red-flowered plant and a white-flowered plant yields all-purple offspring. The flower color trait in radishes is an example of which of the following inheritance patterns? A) a multiple allelic system B) sex linkage C) codominance D) incomplete dominance

incomplete dominance

Melting of ice and thus reduced feeding opportunities for polar bears is occurring because of the ________. A) increase in phytoplankton population B) drying up of lakes and streams C) constant breaking and reforming of hydrogen bonds in water D) increase in CO2 and other greenhouse gases in the atmosphere

increase in CO 2 and other GREENHOUSE gases in the atmosphere

If a pharmaceutical company wished to design a drug to maintain low blood sugar levels, one approach might be to design a compound that does which of the following? A) increases glycogen phosphorylase activity in liver cells B) activates adenylyl cyclase in liver cells C) stimulates G protein activity in liver cells D) increases phosphodiesterase activity in liver cells

increases phosphodiesterase activity in liver cells

Nucleotides can be radiolabeled before they are incorporated into newly forming DNA and, therefore, can be assayed to track their incorporation. In a set of experiments, a student-faculty research team used labeled T nucleotides to study the incorporation of labeled nucleotides into a culture of lymphocytes. They found that the lymphocytes incorporated the labeled nucleotide at a significantly HIGHER LEVEL after a PATHOGEN was introduced into the culture. What might they conclude from this observation? A) The pathogen consumed radiolabeled nucleotides. B) Infection causes lymphocytes to divide more rapidly. C) Infection causes lymphocytes to increase in size. D) Infection causes lymphocyte cultures to skip some parts of the cell cycle.

infection causes lymphocytes to divide more RAPIDLY

German scientist Carl Correns found that the inheritance of variegated color on the leaves of certain plants was determined only by the maternal parent. What phenomenon explains this pattern of inheritance? A) ribosome structure B) inheritance of plastid genes C) genomic imprinting D) sex linkage

inheritance of plastid genes

In a metabolic pathway, succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by malonic acid, a substance that resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the amount of succinate molecules to those of malonic acid reduces the inhibitory effect of malonic acid. What role does malonic acid play with respect to succinate dehydrogenase? A) Malonic acid is a competitive inhibitor. B) Malonic acid blocks the binding of fumarate. C) Malonic acid is a noncompetitive inhibitor. D) Malonic acid is an allosteric regulator.

inhibitor

Which of the following is the most plausible explanation for why an animal cell would be unable to reduce the Ca2+ concentration in its cytosol compared with the extracellular fluid? A) inactivation of calcium-gated ion channels in the cell membrane B) excessive transport of calcium from the cytosol into the endoplasmic reticulum C) insufficient ATP levels in the cytosol D) insufficient levels of protein kinase in the cell

insufficient ATP levels in the cytosol

Lipid-soluble signaling molecules, such as aldosterone, cross the membranes of all cells but affect only target cells because A) only target cells retain the appropriate DNA segments. B) intracellular receptors are present only in target cells. C) only target cells have enzymes that break down aldosterone. D) only in target cells is aldosterone able to initiate the phosphorylation cascade that turns genes on.

intracellular receptors are present only in target cells.

Trace elements are those required by an organism in only minute quantities. Which of the following is a trace element that is required by humans and other vertebrates, but not by other organisms such as bacteria or plants? A) calcium B) iodine C) sodium D) phosphorus

iodine

Diffusion of ions across membranes through specific ion channels is driven by ________. A) active transport pumps B) ion concentration gradients only C) electrical gradients only D) ion electrochemical gradients

ion electrochemical gradients

48) If the cytoplasm of a cell is at pH 7, and the mitochondrial matrix is at pH 8, then the concentration of H+ ions ________. A) is 10 times higher in the cytoplasm than in the mitochondrial matrix B) is 10 times higher in the mitochondrial matrix than in the cytoplasm C) in the cytoplasm is 7/8 the concentration in the mitochondrial matrix D) in the cytoplasm is 8/7 the concentration in the mitochondrial matrix

is 10 times higher in the CYTOPLASM than in the mitochondrial matrix

According to the FLUID MOSAIC MODEL, a membrane ________. A) is composed of a fluid bilayer of phospholipids between two layers of hydrophilic proteins B) is composed of a single layer of fluid phospholipids between two layers of hydrophilic proteins C) is composed of a mosaic of fluid polysaccharides and amphipathic proteins D) is composed of a fluid bilayer of phospholipids with embedded amphipathic proteins

is composed of fluid bilayer of phospholipids with EMBEDDED AMPHIPATHIC proteins

Celery stalks that are immersed in fresh water for several hours become stiff. Similar stalks left in a 0.15 M salt solution become limp. From this we can deduce that the fresh water ________. A) and the salt solution are both hypertonic to the cells of the celery stalks B) is hypotonic and the salt solution is hypertonic to the cells of the celery stalks C) is hypertonic and the salt solution is hypotonic to the cells of the celery stalks D) is isotonic and the salt solution is hypertonic to the cells of the celery stalks

is hypotonic and the salt solution is hypertonic to the cells of the celery stalks

The sodium-potassium pump is called an electrogenic pump because it ________. A) pumps equal quantities of Na+ and K+ across the membrane in opposite directions B) is used to drive the transport of glucose against a concentration gradient C) decreases the voltage difference across the membrane D) generates voltage across the membrane

is used to drive the transport of glucose against a concentration gradient

What is the function of the RELEASE FACTOR during translation in eukaryotes? A) It binds to the stop codon in the A site in place of a tRNA. B) It releases the amino acid from its tRNA to allow the amino acid to form a peptide bond. C) It supplies a source of energy for termination of translation. D) It releases the ribosome from the ER to allow polypeptides into the cytosol.

it BINDS to the STOP CODON in the A site in place of a tRNA

How does the enzyme telomerase meet the challenge of replicating the ends of linear chromosomes? A) It adds a single 5'; cap structure that resists degradation by nucleases. B) It causes specific double-strand DNA breaks that result in blunt ends on both strands. C) It catalyzes the lengthening of telomeres, compensating for the shortening that could occur during replication without telomerase activity. D) It adds numerous GC pairs, which resist hydrolysis and maintain chromosome integrity.

it CATALYZES the lengthening of TELOMERES compensating for the shortening that could occur during replication without telomerase activity

Which of the following is NOT TRUE OF A CODON? A) It may code for the same amino acid as another codon. B) It never codes for more than one amino acid. C) It extends from one end of a tRNA molecule. D) It is the basic unit of the genetic code.

it EXTENDS from one end of tRNA molecule

Which of the following statements correctly describes the effect a NONSENSE MUTATION would have on a gene? A) It changes an amino acid in the encoded protein. B) It has no effect on the amino acid sequence of the encoded protein. C) It introduces a premature stop codon into the mRNA. D) It alters the reading frame of the mRNA.

it INTRODUCES a PREMATURE STOP codon into the mRNA

P680+ is said to be the STRONGEST BIOLOGICAL OXIDIZING agent. Given its function, why is this necessary? A) It is the receptor for the most excited electron in either photosystem of photosynthesis. B) It is the molecule that transfers electrons to plastoquinone (Pq) of the electron transfer system. C) It transfers its electrons to reduce NADP+ to NADPH. D) It obtains electrons from the oxygen atom in a water molecule, so it must have a stronger attraction for electrons than oxygen has.

it OBTAINS electrons from the oxygen atom in a water molecule so it must have a stronger attraction

Which of the following processes correctly describes ALTERNATIVE RNA SPLICING? A) It is a mechanism for increasing the rate of translation. B) It can allow the production of proteins of different sizes and functions from a single mRNA. C) It can allow the production of similar proteins from different RNAs. D) It increases the rate of transcription.

it can allow the production of proteins of different sizes and function from a SINGLE mRNA

Why is CARBON SO IMPORTANT in biology? A) It is a common element on Earth. B) It has very little electronegativity, making it a good electron donor. C) It bonds to only a few other elements. D) It can form a variety of carbon skeletons and host functional groups.

it can form a VARIETY OF CARBON SKELETONS and host functional groups

Which of the following statements correctly describes the function of a SIGNAL PEPTIDE? A) It directs an mRNA molecule into the cisternal space of the ER. B) It terminates translation of messenger RNA. C) It helps target a protein to the ER. D) It signals the initiation of transcription.

it helps TARGET PROTEIN to the ER

Which of the following statements accurately describes the structure of a EUKARYOTIC CHROMOSOME? A) It is composed of a single strand of DNA. B) It is constructed as a series of nucleosomes wrapped around two DNA molecules. C) It has different numbers of genes in different cell types of an organism. D) It is a single linear molecule of double-stranded DNA plus proteins.

it is a SINGLE LINEAR molecule of double stranded DNA plus proteins

Which of the following statements best describes the significance of the TATA box in the promoters of eukaryotes? A) It is the recognition site for the binding of a specific transcription factor. B) It sets the reading frame of the mRNA during translation. C) It is the recognition site for ribosomal binding during translation. D) It is the recognition site for ribosomal binding during transcription.

it is the recognition site for the binding of a SPECIFIC transcription factor

Within a double-stranded DNA molecule, adenine forms hydrogen bonds with thymine, and cytosine forms hydrogen bonds with guanine. What is the significance of the structural arrangement? A) It allows variable width of the double helix. B) It permits complementary base pairing. C) It determines the tertiary structure of a DNA molecule. D) It determines the type of protein produced.

it permits COMPLEMENTARY BASE PAIRING

Which of the following statements summarizes the metabolic results of photorespiration? A) It produces ATP and consumes oxygen and carbon dioxide. B) It produces carbon dioxide and consumes ATP and oxygen. C) It produces oxygen and consumes ATP and carbon dioxide. D) It produces oxygen and ATP and consumes carbon dioxide.

it produces CARBON DIOXIDE consumes ATP

The KIND AND NUMBER OF BONDS an atom can form depends on ________. A) its atomic number B) its electron configuration C) its atomic mass D) the number of particles in its nucleus

its electron configuration

Which of the following properties is associated with a PROTEIN SECRETED from a eukaryotic cell? A) It must be translated by a ribosome that remains free within the cytosol. B) Its signal sequence must target it to the ER, after which it goes to the Golgi. C) Its signal sequence must be cleaved off before the polypeptide can enter the ER. D) Its signal sequence must target it to the plasma membrane, where it causes exocytosis.

its signal sequence must target it to the ER after which it goes to the GOLGI

What is the role of DNA ligase in the elongation of the lagging strand during DNA replication? A) It synthesizes RNA nucleotides to make a primer. B) It joins Okazaki fragments together. C) It unwinds the parental double helix. D) It stabilizes the unwound parental DNA.

joins OKAZAKI fragments together

What are scaffolding proteins? A) microtubule arrays that allow lipid-soluble hormones to get from the cell membrane to the nuclear pores B) large molecules to which several relay proteins attach to facilitate cascade effects C) relay proteins that orient receptors and their ligands in appropriate directions to facilitate complex formation D) proteins that enter the nucleus of a cell to regulate transcription

large molecules to which several relay proteins attach to facilitate cascade effects

You briefly expose bacteria undergoing DNA replication to radioactively labeled nucleotides. When you centrifuge the DNA isolated from the bacteria, the DNA separates into two classes. One class of labeled DNA includes very LARGE molecules (thousands or even millions of nucleotides long), and the other includes SHORT stretches of DNA (several hundred to a few thousand nucleotides in length). Which two classes of DNA do these different samples represent? A) leading strands and Okazaki fragments B) lagging strands and Okazaki fragments C) Okazaki fragments and RNA primers D) leading strands and RNA primers

leading strands and Okazaki fragments

In a human karyotype, chromosomes are arranged in 23 pairs. If we choose one of these pairs, such as pair 14, which of the following do the two chromosomes of the pair have in common? A) length and position of the centromere only B) length, centromere position, and staining pattern only C) length, centromere position, staining pattern, and traits coded for by their genes D) They have nothing in common except that they are X-shaped.

length, centromere position, staining pattern, and traits coded for by their genes

The enzyme phosphofructokinase (PFK) catalyzes a key step in glycolysis. About 10% of Springer spaniels suffer from canine PFK deficiency. Given its critical role in glycolysis, which of the following conditions would be a likely consequence for dogs afflicted with this disorder? A) They would die as embryos. B) They would have elevated blood-glucose levels, which may result in a high incidence of diabetes. C) They would be lethargic and readily tire from exercise. D) They would carry out elevated levels of oxidative phosphorylation.

lethargic and readily tire

Binding of a signaling molecule to which type of receptor leads directly to a change in the distribution of ions on opposite sides of the membrane? A) receptor tyrosine kinase B) G protein-coupled receptor C) ligand-gated ion channel D) steroid receptor

ligand-gated ion channe

Living organisms INCREASE IN COMPLEXITY as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics? A) Living organisms do not obey the second law of thermodynamics, which states that the entropy of an organism increases with each energy transformation. B) The decrease in entropy is associated with growth of an organism. As a consequence of growth, organisms cause a greater increase in entropy in their environment than the decrease in entropy associated with their increased complexity. C) As a consequence of growth, the decrease in entropy of the organism is associated with a corresponding decrease in the entropy of the universe. D) Living organisms are able to transform chemical energy into entropy.

living organisms are able to TRANSFORM CHEMICAL ENERGY into ENTROPY

The experimental approach taken in current BIOLOGICAL INVESTIGATIONS presumes that ________. A) simple organic compounds can be synthesized in the laboratory from inorganic precursors, but complex organic compounds like carbohydrates and proteins can be synthesized only by living organisms B) a life force ultimately controls the activities of living organisms, and this life force cannot be studied by physical or chemical methods C) living organisms are composed of the same elements present in nonliving things, plus a few special trace elements found only in living organisms or their products D) living organisms can be understood in terms of the same physical and chemical laws that can be used to explain all natural phenomena

living organisms can be UNDERSTOOD in terms of the same physical and chemical laws that can be used to explain all NATURAL PHENOMENA

In addition to activating or inhibiting enzymes through allosteric regulation, what other means does a cell use to control enzymatic activity? A) localization of enzymes into specific organelles or membranes B) secretion of enzymes out of the cell C) assembly of enzymes into large aggregates D) altering internal pH

localization of enzymes into specific organelles or membranes

In a chemical reaction, the element 13Al will most preferably ________. A) lose three electrons and become positively charged B) gain five electrons and become negatively charged C) lose five electrons and become positively charged D) gain three electrons and become positively charged

lose three electrons and become positively charged

Apoptosis involves all but which of the following? A) fragmentation of the DNA B) cell-signaling pathways C) lysis of the cell D) digestion of cellular contents by scavenger cells

lysis of the cell

Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large, complex, undigested lipids. Which cellular organelle is most likely defective in this condition? A) the lysosome B) the Golgi apparatus C) the smooth endoplasmic reticulum D) the rough endoplasmic reticulum

lysosome

A bacterium engulfed by a white blood cell through phagocytosis will be digested by enzymes contained in ________. A) lysosomes B) Golgi vesicles C) vacuoles D) secretory vesicles

lysosomes

Asbestos is a material that was once used extensively in construction. One risk from working in a building that contains asbestos is the development of asbestosis caused by the inhalation of asbestos fibers. Cells will take up asbestos by phagocytosis, but are not able to degrade it. As a result, asbestos fibers accumulate in ________. A) the Golgi apparatus B) nuclei C) peroxisomes D) lysosomes

lysosomes

According to the CENTRAL DOGMA, what is the intermediate molecule involved in the flow of information in a cell that should go in the blank? DNA → ________ → Proteins A) mtDNA B) rRNA C) mRNA D) tRNA

mRNA

Which of the following macromolecules leave the nucleus of a eukaryotic cell through pores in the nuclear membrane? A) DNA B) amino acids C) mRNA D) phospholipids

mRNA

Which of the following molecular structures CONTAIN CODONS? A) a protein B) mRNA C) tRNA D) rRNA

mRNA

Which of the following molecules are required for the process of TRANSLATION? A) mRNA, tRNA, DNA, and rRNA B) mRNA, DNA, and rRNA C) mRNA, tRNA, and rRNA D) mRNA, tRNA, and DNA

mRNA, tRNA, rRNA (no DNA)

Francesco Redi What hypothesis was being tested in the initial experiment with open versus sealed jars? A) Spontaneous generation is more likely during the long days of summer. B) The type of meat used affects the likelihood of spontaneous generation. C) Maggots do not arise spontaneously, but from eggs laid by adult flies. D) Spontaneous generation can occur only if meat is exposed to air.

maggots do not arise spontaneously, but from eggs laid by adult flies

Crossing over of chromosomes normally takes place during which of the following processes? A) meiosis II B) meiosis I C) mitosis D) mitosis and meiosis II

meiosis I

The two homologs of a pair move toward opposite poles of dividing cell during A) mitosis. B) meiosis I. C) meiosis II. D) fertilization.

meiosis I.

The voltage across a membrane is called the ________. A) chemical gradient B) membrane potential C) osmotic potential D) electrochemical gradient

membrane potential

What amino acid sequence will be generated, based on the following mRNA codon sequence? 5′-AUG-UCU-UCG-UUA-UCC-UUG-3′ A) Met-Arg-Glu-Arg-Glu-Arg B) Met-Glu-Arg-Arg-Glu-Leu C) Met-Ser-Leu-Ser-Leu-Ser D) Met-Ser-Ser-Leu-Ser-Leu

met-SER-SER-leu-ser-leu

metabolism consists of ALL ENERGY TRANSFORMATION REACTIONS IN an organism

At which stage of mitosis are chromosomes usually photographed in the preparation of a karyotype? A) prophase B) metaphase C) anaphase D) interphase

metaphase

During which of the following processes do homologous pairs of chromosomes align adjacent to one another at the metaphase plate of a cell? A) metaphase of mitosis B) metaphase I of meiosis C) telophase II of meiosis D) metaphase II of meiosis

metaphase I of meiosis

Identical heat lamps are arranged to shine on two identical containers, one containing water and one methanol (wood alcohol), so that each liquid absorbs the same amount of energy minute by minute. The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. Which of the following graphs correctly describes what will happen to the temperature of the water and the methanol?

methanol goes higher than water

Cyanide binds to at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the cyanide will be found within the A) mitochondria. B) ribosomes. C) peroxisomes. D) lysosomes.

mitochondria.

Use the following figure to answer the question. The pedigree in the figure shows the transmission of a trait in a particular family. Based on this pattern of transmission, the trait is most likely ________. A) mitochondrial B) sex-linked dominant C) sex-linked recessive D) autosomal dominant

mitochondrial

Where are the proteins of the electron transport chain located? A) mitochondrial outer membrane B) mitochondrial inner membrane C) mitochondrial intermembrane space D) mitochondrial matrix

mitochondrial inner membrane

Energy released by the electron transport chain is used to pump H+ ions into which location in eukaryotic cells? A) cytoplasm adjacent to the mitochondrial outer membrane B) mitochondrial inner membrane C) mitochondrial intermembrane space D) mitochondrial matrix

mitochondrial intermembrane space

Which organelle is the primary site of ATP synthesis in eukaryotic cells? A) lysosome B) mitochondrion C) Golgi apparatus D) peroxisome

mitochondrion

Which structure is common to plant and animal cells? A) chloroplast B) central vacuole C) mitochondrion D) centriole

mitochondrion

Asexual reproduction occurs during which of the following processes? A) meiosis B) mitosis C) fertilization D) the exchange of chromosomes between organisms of different species

mitosis

You are asked to indicate the type and number of atoms in a molecule. Which representation would work best? A) molecular formula B) structural formula C) ball-and-stick model D) space-filling model

molecular formula

Water is one of the end products of aerobic respiration. What is the source of the oxygen atom used in formation of the water? A) carbon dioxide (CO2) B) glucose (C6H12O6) C) molecular oxygen (O2) D) pyruvate (C3H3O3-)

molecular oxygen (O2)

Which of the following is an example of potential rather than kinetic energy? A) water rushing over Niagara Falls B) light flashes emitted by a firefly C) a molecule of glucose D) a crawling beetle foraging for food

molecule of glucose

A molecule with the chemical formula C6H12O6 is probably a ________. A) fatty acid B) polysaccharide C) nucleic acid D) monosaccharide

monosaccharide

Cytochalasin D is a drug that prevents actin polymerization. A cell treated with cytochalasin D will still be able to carry out which of the following processes? A) divide in two B) contract muscle fibers C) extend pseudopodia D) move vesicles within a cell

move vesicles within a cell

Which of the following membrane activities requires energy from ATP hydrolysis? A) facilitated diffusion of chloride ions across the membrane through a chloride channel B) movement of Na+ ions from a lower concentration in a mammalian cell to a higher concentration in the extracellular fluid C) movement of glucose molecules into a bacterial cell from a medium containing a higher concentration of glucose than inside the cell D) movement of carbon dioxide out of a paramecium

movement of Na+ ions from a lower concentration in a mammalian cell to a higher concentration in the extracellular fluid

A sodium-potassium pump ________. A) moves three potassium ions out of a cell and two sodium ions into a cell while producing ATP for each cycle B) moves three sodium ions out of a cell and two potassium ions into a cell using energy from ATP hydrolysis C) moves three potassium ions out of a cell and two sodium ions into a cell using energy from ATP hydrolysis D) move three sodium ions out of a cell and two potassium ions into a cell and generates an ATP in each cycle

moves three sodium ions out of a cell and two potassium ions into a cell using energy from ATP hydrolysis

Inheritance patterns cannot always be explained by Mendel's models of inheritance. If a pair of homologous chromosomes fails to separate during meiosis I, select the choice that shows the chromosome number of the four resulting gametes with respect to the normal haploid number (n)? A) n + 1; n + 1; n - 1; n - 1 B) n + 1; n - 1; n; n C) n + 1; n - 1; n - 1; n - 1 D) n + 1; n + 1; n; n

n + 1; n + 1; n - 1; n - 1

Even though plants cells carry out photosynthesis, they still use their mitochondria for oxidation of pyruvate. Under what conditions will plant cell mitochondria be active in this process? A) only in photosynthetic cells in the light, while photosynthesis occurs concurrently B) only in cells that store glucose in the form of starch and only in the dark C) in all cells, with or without light D) in photosynthesizing cells in the light, and in other cells in the dark

n all cells, with or without light

Which of these provides evidence of the common ancestry of all life? A) near universality of the genetic code B) structure of the nucleus C) structure of cilia D) structure of chloroplasts

near universality of the genetic code

Suppose a cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from ________. A) a bacterium, but not a eukaryote B) an animal, but not a plant C) nearly any eukaryotic organism D) a plant, but not an animal

nearly any eukaryotic organism

When your body temperature rises on a hot day, the neural and hormonal mechanisms activate sweating. Evaporation of sweat leads to cooling of the body surface. This is an example of ________. A) positive feedback regulation B) negative feedback regulation C) chemical cycling D) emergent properties

negative feedback regulation

In the figure, the DOTS IN THE SPACEe between the two structures represent which of the following? A) receptor molecules B) signal transducers C) neurotransmitters D) hormones

neurotransmitters

Which of the following descriptions best fits the class of molecules known as nucleotides? A) a nitrogenous base and a phosphate group B) a nitrogenous base and a sugar C) a nitrogenous base, a phosphate group, and a sugar D) a sugar and a purine or pyrimidine

nitrogenous base, a phosphate group, and a sugar ALL 3

A man who is a dwarf with achondroplasia and normal vision marries a color-blind woman of normal height. The man's father was six feet tall, and both the woman's parents were of average height. Dwarfism caused by achondroplasia is autosomal dominant, and red-green color blindness is X-linked recessive. How many of their daughters might be expected to be color-blind with achondroplasia? A) none B) half C) one out of four D) three out of four

none

When the atoms involved in a covalent bond have the same electronegativity, what type of bond results? A) an ionic bond B) a hydrogen bond C) a nonpolar covalent bond D) a polar covalent bond

nonpolar covalent

Bonds between two atoms that are equally electronegative are ________. A) hydrogen bonds B) polar covalent bonds C) nonpolar covalent bonds D) ionic bonds

nonpolar covalent bonds

The difference between pinocytosis and receptor-mediated endocytosis is that ________. A) pinocytosis brings only water molecules into the cell, but receptor-mediated endocytosis brings in other molecules as well B) pinocytosis increases the surface area of the plasma membrane, whereas receptor-mediated endocytosis decreases the plasma membrane surface area C) pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectivity D) pinocytosis can concentrate substances from the extracellular fluid, but receptor-mediated endocytosis cannot

nonselective

In E. coli, to repair a thymine dimer by nucleotide excision repair, in which order do the necessary enzymes act? A) nuclease, DNA polymerase, RNA primase B) helicase, DNA polymerase, DNA ligase C) DNA ligase, nuclease, helicase D) nuclease, DNA polymerase, DNA ligase

nuclease, DNA polymerase, DNA ligase

The relation between amino acid and polypeptide is similar to the relation between ________. A) nucleotide and nucleic acid B) triglycerides and steroids C) phospholipid and plasma membrane D) glycogen and glucose

nucleotide and nucleic acid

As letters are to English language, ________ is/are to genetic information. A) proteins B) nucleotides C) DNA double helix D) A and B

nucleotides

We can be sure that a mole of table sugar and a mole of vitamin C are equal in their A) mass. B) volume. C) number of atoms. D) number of molecules.

number of MOLECULES

Carbon-14 has the same ________. A) atomic number and atomic mass as carbon-12 B) atomic number and thus number of neutrons as carbon-13 C) atomic mass as both carbon-12 and carbon-13 D) number of protons but more neutrons than carbon-12

number of protons but more neutrons than carbon-12

Use the figure to answer the question. Refer to the metabolic pathway illustrated. If A, B, and C are all required for growth, a strain mutant for the gene encoding enzyme (B) would be able to grow on medium supplemented with which of the following nutrient(s)? A) nutrient A only B) nutrient B only C) nutrient C only D) nutrients A and C

nutrient C only

Mendel continued some of his experiments into the F2 or F3 generation in order to ________. A) obtain a larger number of offspring on which to base statistics B) observe whether or not a recessive trait would reappear C) observe whether or not the dominant trait would reappear D) distinguish which alleles were segregating

observe whether or not a recessive trait would reappear

In receptor-mediated endocytosis, receptor molecules initially project to the outside of the cell. Where do they end up after endocytosis? A) on the outside of vesicles B) on the inside surface of the cell membrane C) on the inside surface of the vesicle D) on the outer surface of the nucleus

on the inside surface of the vesicle

Refer to the information and figure below to answer the following questions. A certain (hypothetical) organism is diploid, has either blue or orange wings as the consequence of one of its genes on chromosome 12, and has either long or short antennae as the result of a second gene on chromosome 19, as shown in the figure. 38) A certain female's number 12 chromosomes both have the blue gene and number 19 chromosomes both have the long gene. As cells in her ovaries undergo meiosis, which of the following combinations of genes and chromosomes will her eggs have? A) either two number 12 chromosomes with blue genes or two with orange genes B) either two number 19 chromosomes with long genes or two with short genes C) either one blue or one orange gene in addition to either one long or one short gene D) one chromosome 12 with one blue gene and one chromosome 19 with one long gene

one chromosome 12 with one blue gene and one chromosome 19 with one long gene

If a female of this species has one chromosome 12 with a blue gene and another chromosome 12 with an orange gene, and has both number 19 chromosomes with short genes, which of the following combinations of genes will her eggs have? A) only blue short gene eggs B) only orange short gene eggs C) one half blue short and one half orange short gene eggs D) three fourths blue short and one fourth orange short gene eggs

one half blue short and one half orange short gene eggs

Compared with 31 P, the radioactive isotope 32 P has A) a different atomic number. B) one more proton. C) one more electron. D) one more neutron.

one more neutron

A covalent bond is likely to be polar when ________. A) one of the atoms sharing electrons is more electronegative than the other atom B) the two atoms sharing electrons are equally electronegative C) carbon is one of the two atoms sharing electrons D) the two atoms sharing electrons are of the same elements

one of the atoms sharing electrons is more electronegative than the other atom

In the following structure where A and B represent two different elements, the valency of A is ________ and B is ________. A) one; three B) one; five C) three; five D) eight; eight

one; three

Which of the following types of cells are affected most by telomere shortening? A) only prokaryotic cells B) only eukaryotic cells C) cells in prokaryotes and eukaryotes D) only animal cells

only EUKARYOTIC

How might a SINGLE BASE SUBSTITUTION in the sequence of a gene affect the amino acid sequence of a protein encoded by the gene? A) Only a single amino acid could change, because the reading frame would be unaffected. B) The amino acid sequence would be substantially altered, because the reading frame would change with a single base substitution. C) All amino acids following the substitution would be affected, because the reading frame would be shifted. D) It is not possible for a single base substitution to affect protein structure, because each codon is three bases long.

only a SINGLE AMINO ACID could change, because the readying frame would be unaffected

Which of the following statements is an important CONSEQUENCE OF THE FIRST LAW of thermodynamics for a living organism? A) The energy content of an organism is constant. B) An organism ultimately must obtain all of the necessary energy for life from its environment. C) The entropy of an organism decreases with time as the organism grows in complexity. D) Organisms grow by converting energy into organic matter.

organism ULTIMATELY must OBTAIN ALL NECESSARY energy for life from its environment

The figure shows the absorption spectrum for CHLOROPHYLL A and the ACTION SPECTRUM for photosynthesis. Why are they different? A) Green and yellow wavelengths inhibit the absorption of red and blue wavelengths. B) Oxygen given off during photosynthesis interferes with the absorption of light. C) Other pigments absorb light in addition to chlorophyll a. D) Aerobic bacteria take up oxygen, which changes the measurement of the rate of photosynthesis.

other PIGMENTS absorbs light in addition to chlorophyll a

A covalent chemical bond is one in which ________. A) electrons are removed from one atom and transferred to another atom so that the two atoms become oppositely charged B) protons and neutrons are shared by two atoms so as to satisfy the requirements of both atoms C) outer-shell electrons of two atoms are shared so as to satisfactorily fill their respective orbitals D) outer-shell electrons of one atom are transferred to fill the inner electron shell of another atom

outer-shell ELECTRONS of two atoms are SHARED so as to satisfactorily fill their respective orbitals

Carbon dioxide (CO2) is released during which of the following stages of cellular respiration? A) glycolysis and the oxidation of pyruvate to acetyl CoA B) oxidation of pyruvate to acetyl CoA and the citric acid cycle C) oxidative phosphorylation and fermentation D) fermentation and glycolysis

oxidation of pyruvate to acetyl CoA and the citric acid cycle

The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is A) oxygen. B) water. C) NAD+. D) pyruvate.

oxygen.

What is the pH of a solution with a hydroxyl ion (OH-) concentration of 10-10 M? A) pH 2 B) pH 4 C) pH 10 D) pH 12

pH 4

Which of the following processes includes all the others? A) osmosis B) diffusion of a solute across a membrane C) passive transport D) transport of an ion down its electrochemical gradient

passive transport

A phospholipid bilayer with equal amounts of saturated and unsaturated fatty acids displays a specific permeability to glucose. What effect will increasing the proportion of UNSATURATED FATTY acids in the bilayer have on the membrane's PERMEABILITY TO GLUCOSE? A) Permeability to glucose will increase. B) Permeability to glucose will decrease. C) Permeability to glucose will stay the same. D) Permeability will decrease initially then increase as the bilayer fills with glucose.

permeability will INCREASE

Which cell would be best for studying lysosomes? A) muscle cell B) nerve cell C) bacterial cell D) phagocytic white blood cell

phagocytic white blood cel

An organism with a cell wall would most likely be unable to take in materials through ________. A) osmosis B) active transport C) phagocytosis D) facilitated diffusion

phagocytosis

White blood cells engulf bacteria using ________. A) phagocytosis B) pinocytosis C) osmosis D) receptor-mediated exocytosis

phagocytosis

The activity of adenylyl cyclase is essentially the opposite of which of the following enzymes? A) protein kinase B) protein phosphatase C) phosphodiesterase D) phosphorylase

phosphodiesterase

An inhibitor of which of the following enzymes could be used to block the release of calcium from the endoplasmic reticulum? A) serine/threonine kinases B) phosphodiesterase C) phospholipase C D) adenylyl cyclase

phospholipase C

Which of the following statements best describes the relationship between PHOTOSYNTHESIS AND CELLULAR RESPIRATION? A) Cellular respiration runs the biochemical pathways of photosynthesis in reverse. B) Photosynthesis stores energy in complex organic molecules; cellular respiration releases energy from complex organic molecules. C) Photosynthesis occurs only in plants; cellular respiration occurs only in animals. D) Photosynthesis is catabolic; cellular respiration is anabolic.

photosynthesis STORES ENERGY in complex ORGANIC MOLECULES cellular respiration releases

Under what conditions do PHOTOSYNTHESIS and CELLULAR RESPIRATION occur in plants? A) Photosynthesis and cellular respiration occur only in the light. B) Photosynthesis occurs only in the light, and cellular respiration occurs only in the dark. C) Photosynthesis occurs only in the light, and cellular respiration occurs in both the dark and the light. D) Photosynthesis and cellular respiration occur in both the dark and the light.

photosynthesis occurs only in light, cellular respiration occurs in light . AND dark

Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely A) an animal cell in the process of cytokinesis. B) a plant cell in the process of cytokinesis. C) a bacterial cell dividing. D) a plant cell in metaphase.

plant cell in the process of cytokinesis.

How is PLANT CELL CYTOKINESIS different from ANIMAL CELL CYTOKINESIS? A) The contractile filaments found in plant cells are structures composed of carbohydrates; the cleavage furrow in animal cells is composed of contractile proteins. B) Plant cells deposit vesicles containing cell wall building blocks on the metaphase plate; animal cells form a cleavage furrow. C) The structural proteins of plant cells separate the two cells; in animal cells, a cell membrane separates the two daughter cells. D) Plant cells divide after metaphase but before anaphase; animal cells divide after anaphase.

plant cells DEPOSIT VESICLES containing cell wall building blacks on the metaphase plate; animals form a CLEAVAGE FURROW

Which of the following structures form cytoplasmic channels that connect adjacent plant cells through the cell walls? A) desmosomes B) gap junctions C) plasmodesmata D) tight junctions

plasmodesmata

Which of the following inheritance patterns describes the ability of a single allele to have multiple phenotypic effects? A) incomplete dominance B) multiple alleles C) pleiotropy D) epistasis

pleiotropy

In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by ________. A) hydrogen bonds B) nonpolar covalent bonds C) polar covalent bonds D) ionic bonds

polar covalent bonds

A localized group of organisms that belong to the same species is called a ________. A) community B) population C) ecosystem D) family

population

The difference between an ALDOSE sugar and a KETOSE sugar is ________. A) the number of carbon atoms B) the position of the hydroxyl groups C) the position of the carbonyl group D) the ring form and the linear chain

position of the CARBONYL group

Use the following figure to answer the question. Based on your knowledge of the polarity of water molecules, the solute molecule depicted is most likely ________. A) positively charged B) negatively charged C) without charge D) nonpolar

positively charged

What makes lipids/fats hydrophobic? A) their long carbon skeleton B) the carboxyl group at one end of the molecule C) the glycerol moiety D) presence of relatively nonpolar C—H bonds

presence of relatively nonpolar C—H bonds

You disrupt all hydrogen bonds in a protein. What level of structure will be preserved? A) primary structure B) secondary structure C) tertiary structure D) quaternary structure

primary structure

A cell with a predominance of rough endoplasmic reticulum is most likely ________. A) producing large quantities of proteins for secretion B) producing large quantities of proteins in the cytosol C) producing large quantities of carbohydrates to assemble an extensive cell wall matrix D) producing large quantities of carbohydrates for storage in the vacuole

producing large quantities of proteins for secretion

Which of the following statements accurately describes the differences between DNA replication in prokaryotes and DNA replication in eukaryotes? A) Prokaryotic chromosomes have histones, whereas eukaryotic chromosomes do not. B) Prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many. C) The rate of elongation during DNA replication is slower in prokaryotes than in eukaryotes. D) Prokaryotes produce Okazaki fragments during DNA replication, but eukaryotes do not.

prokaryotic chromosomes have a SINGLE ORIGIN OF REPLICATION, whereas eukaryotic chromosomes have many

At which phase of the cell cycle do CENTROLIES begin to MOVE APART in animal cells? A) anaphase B) telophase C) metaphase D) prophase

prophase

When chiasmata can first be seen in cells using a microscope, which of the following processes has most likely occurred? A) meiosis II B) anaphase II C) prophase I D) the separation of homologs

prophase I

Which of the following results would most likely be an immediate result of a growth factor binding to its receptor? A) protein kinase activity B) adenylyl cyclase activity C) cAMP activity D) phosphorylase activity

protein kinase activity

In mitochondria, exergonic redox reactions A) are the source of energy driving prokaryotic ATP synthesis. B) provide the energy that establishes the proton gradient. C) reduce carbon atoms to carbon dioxide. D) are coupled via phosphorylated intermediates to endergonic processes.

provide the energy that establishes the proton gradient

Which of the following processes generates a proton-motive force in mitochondria? A) the flow of protons through ATP synthase down their concentration gradient B) the reduction of NAD+ by the first electron carrier in the electron transport chain C) lowering of pH in the mitochondrial matrix D) pumping of hydrogen ions from the mitochondrial matrix across the inner membrane and into the intermembrane space

pumping of hydrogen ions from the mitochondrial matrix across the inner membrane and into the intermembrane space

Radish flowers may be red, purple, or white. A cross between a red-flowered plant and a white-flowered plant yields all-purple offspring. The part of the radish we eat may be oval or long, with long being the dominant trait. If true-breeding red long radishes are crossed with true-breeding white oval radishes, the F1 will be expected to exhibit which of the following phenotypes? A) red and long B) white and long C) purple and long D) purple and oval

purple and long

What is the oxidizing agent in the following reaction? Pyruvate + NADH + H- Lactate + NAD- A) oxygen B) NADH C) lactate D) pyruvate

pyruvate

Hemoglobin is ________. A) a tertiary protein with two polypeptides B) a quaternary protein with two polypeptides C) a tertiary protein with four polypeptides D) a quaternary protein with four polypeptides

quaternary protein with four polypeptides

Which of the following activities would be inhibited by a drug that specifically blocks the addition of phosphate groups to proteins? A) binding of G proteins to G protein-coupled receptors B) ligand-gated ion channel signaling pathways C) adenylyl cyclase activity D) receptor tyrosine kinase activity

receptor tyrosine kinase activity

One of the major categories of receptors in the plasma membrane functions by forming dimers, adding phosphate groups, and then activating relay proteins. Which type does this? A) G protein-coupled receptors B) ligand-gated ion channels C) steroid receptors D) receptor tyrosine kinases

receptor tyrosine kinases

Pseudohypertrophic muscular dystrophy is a human disorder that causes gradual deterioration of the muscles. Only boys are affected, and they are always born to phenotypically normal parents. Due to the severity of the disease, the boys die in their teens. Is this disorder likely to be caused by a dominant or recessive allele? Is the inheritance of this trait sex-linked or autosomal? A) dominant, sex-linked B) recessive, autosomal C) recessive, sex-linked D) incomplete dominant, sex-linked

recessive, sex-linked

Which of the following characteristics would you expect of a eukaryotic organism that lacks the enzyme telomerase? A) a high probability of somatic cells becoming cancerous B) an inability to produce Okazaki fragments C) an inability to repair thymine dimers D) a reduction in chromosome length in gametes

reduction in chromosome LENGTH IN GAMETES

Which of the following processes is driven by chemiosmosis? A) substrate-level phosphorylation B) oxidative phosphorylation C) ATP hydrolysis D) reduction of NAD+ to NADH

reduction of NAD+ to NADH

To understand the chemical basis of inheritance, we must understand the molecular structure of DNA. This is an example of the application of which concept to the study of biology? A) evolution B) emergent properties C) reductionism D) feedback regulation

reductionism

Theodor W. Engelmann illuminated a filament of algae with light that passed through a prism, thus exposing different segments of algae to different wavelengths of light. He added aerobic bacteria and then noted in which areas the bacteria congregated. He noted that the largest groups were found in the areas illuminated by the red and blue light. Which of the following statements describes a relationship that ENGLEMANNs experiment helped to determine? A) the relationship between wavelength of light and the rate of aerobic respiration B) the relationship between wavelength of light and the amount of heat released C) the relationship between wavelength of light and the rate of photosynthesis D) the relationship between carbon dioxide concentration and the rate of photosynthesis

relationship between wavelength of light and RATE OF PHOTOSYNTHESIS

After the first replication was observed in their experiments testing the nature of DNA replication, Meselson and Stahl could be confident of which of the following conclusions? A) Replication is semi-conservative. B) Replication is not dispersive. C) Replication is not conservative. D) Replication is neither dispersive nor conservative.

replication is NOT CONSERVATIVE

Which of the following does not occur during mitosis? A) condensation of the chromosomes B) replication of the DNA C) separation of sister chromatids D) spindle formation

replication of the DNA

In DNA replication in E. coli, the enzyme primase is used to attach a 5 to 10 base ribonucleotide strand complementary to the parental DNA strand. The RNA strand serves as a starting point for the DNA polymerase that replicates the DNA. If a mutation occurred in the primase gene, which of the following results would you expect? A) Replication would only occur on the leading strand. B) Replication would only occur on the lagging strand. C) Replication would not occur on either the leading or lagging strand. D) Replication would not be affected as the enzyme primase in involved with RNA synthesis.

replication would NOT OCCUR ON EITHER the leading or lagging strand

The chemical reaction illustrated ________. A) is a hydrolysis reaction B) results in a peptide bond C) joins two fatty acids together D) links two polymers to form a monomer

results in a peptide bond

Which of the following macromolecules enter the nucleus of a eukaryotic cell through pores in the nuclear membrane? A) ribosomal proteins B) mRNA C) rRNA D) phospholipids

ribosomal proteins

Which of the following is present in a prokaryotic cell? A) mitochondrion B) ribosome C) nuclear envelope D) chloroplast

ribosome

Which of the following are found in plant, animal, and bacterial cells? A) mitochondria B) ribosomes C) chloroplasts D) endoplasmic reticulum

ribosomes

In cattle, roan coat color (mixed red and white hairs) occurs in the heterozygous (CRCW) offspring of red (CRCR) and white (CWCW) homozygotes. Which of the following crosses would produce offspring in the ratio of 1 red:2 roan:1 white? A) red × white B) roan × roan C) white × roan D) red × roan

roan × roan

Which of the following is the most common pathway taken by a newly synthesized protein that will be secreted by a cell? A) rough ER → Golgi → transport vesicle → nucleus B) Golgi → rough ER → lysosome → transport vesicle → plasma membrane C) rough ER → Golgi → transport vesicle → plasma membrane D) rough ER → lysosome → transport vesicle → plasma membrane

rough ER → Golgi → transport vesicle → plasma membrane

The label on a container of margarine lists "hydrogenated vegetable oil" as the major ingredient. Hydrogenated vegetable oil ________. A) is solid at room temperature B) has more "kinks" in the fatty acid chains C) has fewer trans fatty acids D) is less likely to clog arteries

s solid at room temperature

Elements 72 Zn, 75 As, and 74 Ge have the ________. A) same number of protons B) same number of protons and electrons C) same number of neutrons D) same number of neutrons and electrons

same number of NEUTRONS

Increased atmospheric CO2 concentrations might have what effect on seawater? A) Seawater will become more alkaline, and carbonate concentrations will decrease. B) There will be no change in the pH of seawater, because carbonate will turn to bicarbonate. C) Seawater will become more acidic, and carbonate concentrations will decrease. D) Seawater will become more acidic, and carbonate concentrations will increase.

seawater will become more acidic, carbonate will DECREASE

Vinblastine, a drug that inhibits microtubule polymerization, is used to treat some forms of cancer. Cancer cells given vinblastine would be unable to ________. A) form cleavage furrows during cell division B) migrate by amoeboid movement C) separate chromosomes during cell division D) maintain the shape of the nucleus

separate chromosomes during cell division

Which of the following provides the information necessary to stipulate a protein's 3-D shape? A) peptide bonds between different amino acids B) sequence of amino acids in the polypeptide chain C) side chains of various amino acids D) number of water molecules in the vicinity

sequence of amino acids in the polypeptide chain

Which of the following amino acids are most frequently phosphorylated by protein kinases in the cytoplasm during signal transduction? A) tyrosines B) glycine and histidine C) serine and threonine D) glycine and glutamic acid

serine and threonine

The temperature at which an alligator's egg is incubated will determine the sex of the offspring. The dependent and the independent variables in this experiment are ________. A) sex of the baby alligator and temperature respectively B) temperature and sex of the baby alligator respectively C) size of the incubator and size of the baby alligator respectively D) number of offspring and temperature in the incubator respectively

sex of the baby alligator and the temperature respectively

Which of the following processes facilitates the fastest way for organisms to adapt to a changing environment? A) mutation B) asexual reproduction C) sexual reproduction D) mitosis

sexual reproduction

The solutions in the two arms of this U-tube are separated by a membrane that is permeable to water and glucose but not to sucrose. Side A is half-filled with a solution of 2 M sucrose and 1 M glucose. Side B is half-filled with 1 M sucrose and 2 M glucose. Initially, the liquid levels on both sides are equal. In the U-tube illustrated above, ________. A) side A is hypertonic to side B B) side A is hypotonic to side B C) side A is isotonic to side B D) side A is more turgid than side B

side A is ISOTONIC to side B

An atom has four electrons in its valence shell. What types of covalent bonds is it capable of forming? A) single, double, or triple B) single and double only C) single bonds only D) double bonds only

single, double, or triple

Meiosis II is similar to mitosis in that A) sister chromatids separate during anaphase. B) DNA replicates before the division. C) the daughter cells are diploid. D) homologous chromosomes synapse.

sister chromatids separate during anaphase.

An ion with six protons, seven neutrons, and a charge of 2+ has an atomic number of ________. A) four B) five C) six D) seven

six

What is the maximum number of hydrogen atoms that can be covalently bonded in a molecule containing two carbon atoms? A) two B) four C) six D) eight

six

Which of the following phenotypes is an example of polygenic inheritance? A) pink flowers in snapdragons B) the ABO blood group in humans C) white and purple flower color in peas D) skin pigmentation in humans

skin pigmentation in humans

Carbon dioxide in the atmosphere dissolves with the raindrops. The pH of raindrops is ________. A) slightly acidic B) slightly basic C) same as pure water D) depends on the altitude where rain drops are formed

slightly acidic

The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and, therefore, abundant in liver cells? A) rough endoplasmic reticulum B) smooth endoplasmic reticulum C) Golgi apparatus D) nuclear envelope

smooth endoplasmic reticulum

Water has many exceptional and useful properties. Which is the rarest property among compounds? A) Water is a solvent. B) Solid water is less dense than liquid water. C) Water has a high heat capacity. D) Water has surface tension.

solid water is LESS DENSE than liquid water

Which of the following statements is TRUE? A) Carbon, hydrogen, oxygen, and calcium are the most abundant elements of living matter. B) Some naturally occurring elements are toxic to organisms. C) All life requires the same essential elements. D) A patient suffering from a goiter should not consume seafood.

some naturally occurring elements are toxic to organisms

To act as an effective coolant in a car's radiator, a substance has to have the capacity to absorb a great deal of heat. You have a reference book with tables listing the physical properties of many liquids. In choosing a coolant for your car, which table would you check first? A) pH B) density at room temperature C) heat of vaporization D) specific heat

specific heat

For a chemotherapeutic drug to be useful for treating cancer cells, which of the following characteristics is most desirable? A) It is safe enough to prevent all apoptosis. B) It does not interfere with metabolically active cells. C) It specifically inhibits cells entering G0. D) It specifically inhibits rapidly dividing cells.

specifically inhibits rapidly dividing cells.

Why is a steam burn more severe than a hot water burn? A) Burns caused by liquids are always milder. B) Steam can penetrate into the skin. C) Steam contains more energy than water. D) Water evaporates and leaves the surface faster and helps in cooling.

steam contains MORE ENERGY than water

The molecule shown the figure is a ________. A) fatty acid B) steroid C) triacylglycerol D) phospholipid

steroid

Rank, from low to high, the pH of blood, stomach acid, and urine. A) blood, urine, and stomach acid B) stomach acid, blood, and urine C) urine, blood, stomach acid D) stomach acid, urine, blood

stomach acid, urine, blood

The figure shows the structures of GLUCOSE AND FRUCTOSE. These two molecules are ________. A) isotopes B) enantiomers C) cis-trans isomers D) structural isomers

structural isomers

Use the following figure to answer the question. (in line/ straight/linear) The two molecules shown in the figures are best described as ________. A) enantiomers B) structural isomers C) cis-trans isomers D) chain length isomers

structural isomers

ORGANIC CHEMISTRY is currently defined as A) the study of compounds made only by living cells. B) the study of carbon compounds. C) the study of natural (as opposed to synthetic) compounds. D) the study of hydrocarbons.

study of carbon compounds

Based on electron configuration, which of the elements in the figure would exhibit a chemical behavior most like that of oxygen? A) carbon B) nitrogen C) sulfur D) phosphorus

sulfur

Plants convert ________. A) chemical energy to mechanical energy. B) sunlight to mechanical energy. C) sunlight to chemical energy. D) mechanical energy to chemical energy.

sunlight to chemical energy

Which of the following processes occurs in meiosis but not in mitosis? A) chromosome replication B) synapsis of chromosomes C) alignment of chromosomes at the equator D) condensation of chromosomes

synapsis of chromosomes

A cell with a predominance of smooth endoplasmic reticulum is likely specialized to ________. A) store large quantities of water B) import and export large quantities of protein C) actively secrete large quantities of protein D) synthesize large quantities of lipids

synthesize large quantities of lipids

HORMONES are chemical substances produced in one organ that are released into the bloodstream and affect the function of a target organ. Which of the following conditions is required for the TARGET ORGAN to respond to a particular hormone? A) Cells in the target organ must modify their plasma membranes to allow the hormone to enter the cytoplasm. B) The target organ must be the same as the organ that produced the hormone. C) The target organ must have the opposite mating type of the organ that produced the hormone. D) The target organ must have receptors that recognize and bind the hormone molecule.

target organ must have RECEPTORS THAN RECOGNIZE and bind to the HORMONE MOLECULE

Which branch of biology is concerned with the naming and classifying of organisms? A) informatics B) taxonomy C) genomics D) evolution

taxonomy

The application of scientific knowledge for some specific purpose is known as ________. A) technology B) deductive science C) inductive science D) pure science

technology

Telomere shortening puts a limit on the number of times a cell can divide. Research has shown that telomerase can extend the life span of cultured human cells. How might ADDING TELEMORASE AFFECT CELLULAR AGING? A) Telomerase will speed up the rate of cell proliferation. B) Telomerase eliminates telomere shortening and retards aging. C) Telomerase shortens telomeres, which delays cellular aging. D) Telomerase would have no effect on cellular aging.

telemorase eliminates telomere shortening and RETARDS aging

Most cells cannot harness heat to perform work because A) heat does not involve a transfer of energy. B) cells do not have much thermal energy; they are relatively cool. C) temperature is usually uniform throughout a cell. D) heat can never be used to do work.

temperature is usually uniform throughout a cell.

A controlled experiment is one that A) proceeds slowly enough that a scientist can make careful records of the results. B) tests experimental and control groups in parallel. C) is repeated many times to make sure the results are accurate. D) keeps all variables constant.

tests experimental and control groups in parallel

In the polymerization of DNA, a phosphodiester bond is formed between a phosphate group of the nucleotide being added and which of the following atoms or molecules of the last nucleotide in the polymer? A) the 5' phosphate B) C6 C) the 3' OH D) a nitrogen from the nitrogen-containing base

the 3' OH

What is the major structural difference between STARCH and GLYCOGEN? A) the types of monosaccharide subunits in the molecules B) the type of glycosidic linkages in the molecule C) whether glucose is in the α or β form D) the amount of branching that occurs in the molecule

the AMOUNT of BRANCHING that occurs in the molecule

In a healthy eukaryotic cell, the rate of DNA repair is typically equal to the rate of DNA mutation. When the RATE OF REPAIR LAGS behind the rate of mutation, what is a possible fate of the cell? A) The cell can be transformed into a cancerous cell. B) RNA may be used instead of DNA as inheritance material. C) DNA replication will proceed more quickly. D) DNA replication will continue by a new mechanism.

the CELL can be transformed into a CANCEROUS cell

The COMPLEXITY AND VARIETY of organic molecules is due to ________. A) the chemical versatility of carbon atoms B) the variety of rare elements in organic molecules C) the diverse bonding patterns of nitrogen D) their interaction with water

the CHEMICAL versatility of CARBON atoms

Which of the following statements is a reasonable explanation for why unsaturated fatty acids help keep a membrane MORE FLUID AT LOWER TEMPERATURES? A) The double bonds form kinks in the fatty acid tails, preventing adjacent lipids from packing tightly. B) Unsaturated fatty acids have a higher cholesterol content, which prevents adjacent lipids from packing tightly. C) Unsaturated fatty acids are more nonpolar than saturated fatty acids. D) The double bonds block interaction among the hydrophilic head groups of the lipids.

the DOUBLE BONDS form KINKS in the fatty acid tails, preventing adjacent lipids from packing tightly

What are telomeres? A) the structures that hold two sister chromatids together B) enzymes that elongate the DNA strand during replication C) the sites of origin of DNA replication D) the ends of linear chromosomes

the ENDS of LINEAR chromosomes

One of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3). Carbonic acid is a weak acid that, when placed in an aqueous solution, dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion (H+). (See figure.) If the pH of blood drops, one would expect ________. A) a decrease in the concentration of H2CO3 and an increase in the concentration of HCO3- B) the concentration of bicarbonate ions (HCO3-) to increase C) the HCO3- to act as a base and remove excess H+ by the formation of H2CO3 D) the HCO3- to act as an acid and remove excess H+ by the formation of H2CO3

the HCO3- to act as a BASE and remove excess H+ by formation of H2CO3

Which of the following statements correctly describes the difference between the leading strand and the lagging strand in DNA replication? A) The leading strand is synthesized in the 3' → 5' direction in a discontinuous fashion, while the lagging strand is synthesized in the 5' → 3' direction in a continuous fashion. B) The leading strand is synthesized continuously in the 5' → 3' direction, while the lagging strand is synthesized discontinuously in the 5' → 3' direction. C) The leading strand requires an RNA primer, whereas the lagging strand does not. D) There are different DNA polymerases involved in elongation of the leading strand and the lagging strand.

the LEADING strand is synthesized CONTINUOUSLY in the 5' > 3' direction, while the LAGGING is synthesized DISCONTINUOUSLY

In an experimental situation, a student researcher INSERTS an mRNA molecule into a eukaryotic cell after she has removed its 5′ cap and poly-A tail. Which of the following processes would you expect her to find to have occurred? A) The mRNA is quickly converted into a ribosomal subunit. B) The cell adds a new poly-A tail to the mRNA. C) The mRNA attaches to a ribosome and is translated, but more slowly. D) The molecule is digested by enzymes because it is not protected at the 5′ end.

the MOLECULE is DIGESTED by enzymes because it is not protected at the 5' end

Researchers found a strain of E. coli bacteria that had mutation rates ONE HUNDRED TIMES HIGHER than normal. Which of the following statements correctly describes the most likely cause of these results? A) The single-strand binding proteins were malfunctioning during DNA replication. B) There were one or more base pair mismatches in the RNA primer. C) The proofreading mechanism of DNA polymerase was not working properly. D) The DNA polymerase was unable to add bases to the 3′ end of the growing nucleic acid chain.

the PROOFREADING mechanism of DN polymerase was not working properly

In bacteria, there are 61 mRNA codons that specify an amino acid, but only 45 tRNAs. Which of the following statements explains this fact? A) Some tRNAs have anticodons that recognize four or more different codons. B) The rules for base pairing between the third base of a codon and tRNA are flexible. C) Many codons are never used, so the tRNAs that recognize them are dispensable. D) The DNA codes for all 61 tRNAs, but some are then destroyed.

the RULES for base pairing between the third base of a codon and tRNA are FLEXIBLE

Which of the following processes is the FIRST EVENT to take place in TRANSLATION in eukaryotes? A) base pairing of activated methionine-tRNA to AUG of the messenger RNA B) binding of the larger ribosomal subunit to smaller ribosomal subunits C) the ribosome reaches a stop codon D) the small subunit of the ribosome recognizes and attaches to the 5′ cap of mRNA

the SMALL SUBUNIT of the ribosome recognizes and attaches to the 5' cap of mRNA

Which of the following characteristics is directly related to the CODING OF A SINGLE AMINO ACID during the process of translation? A) the base sequence of the tRNA B) the amino acetyl tRNA synthase C) the three-base sequence of mRNA D) the complementarity of DNA and RNA

the THREE BASE sequence of mRNA

Cell membranes have DISTINCT INSIDE AND OUTSIDE FACES. Which of the following statements is the most likely explanation for the membrane's ASYMMETRICAL nature? A) Since the cell membrane forms a border between one cell and another in tightly packed tissues such as epithelium, the membrane must be asymmetrical. B) Since cell membranes communicate signals from one organism to another, the cell membranes must be asymmetrical. C) The two sides of a cell membrane face different environments and carry out different functions. D) Proteins only function on the cytoplasmic side of the cell membrane, which results in the membrane's asymmetrical nature.

the TWO SIDES of a cell membrane face different environments and carry out different functions

In the structural organization of many eukaryotic genes, INDIVIDUAL EXONS may be related to which of the following? A) the sequence of the intron that immediately precedes each exon B) the number of polypeptides making up the functional protein C) the various domains of the polypeptide product D) the number of start sites for transcription

the VARIOUS DOMAINS of the polypeptide product

Which statement is true of all atoms that are anions? A) The atom has more electrons than protons. B) The atom has more protons than electrons. C) The atom has fewer protons than does a neutral atom of the same element. D) The atom has more neutrons than protons.

the atom has more ELECTRONS than PROTONS

Which of the following is true when comparing an uncatalyzed reaction to the same reaction with a catalyst? A) The catalyzed reaction will be slower. B) The catalyzed reaction will have the same ∆G. C) The catalyzed reaction will have higher activation energy. D) The catalyzed reaction will consume all of the catalyst.

the catalyzed reaction will have the same ∆G

If a cell were UNABLE TO PRODUCE HISTONE proteins, which of the following results would be a likely effect on the cell? A) There would be an increase in the amount of DNA produced during replication. B) The cell's DNA could not be packed into its nucleus. C) Spindle fibers would not form during prophase. D) Amplification of other genes would compensate for the lack of histones.

the cell's DNA could not be PACKED into its nucleus

During which of the following metabolic processes is most of the CO2 from the catabolism of glucose is released? A) glycolysis B) electron transport C) oxidation of pyruvate to acetyl-CoA D) the citric acid cycle

the citric acid cycle

Use the following figure to answer the question. ;"A"t; is ________; &"B"; is ________. A) the most recent species to evolve on Earth; an ancestor of group "A" B) the most recent species to evolve on Earth; the last common ancestor of Archaea and Eukarya C) the common ancestor of all life; the common ancestor of Bacteria and Archaea D) the common ancestor of all life; the last common ancestor of Archaea and Eukarya

the common ancestor of all life; the last common ancestor of archaea and eukarya

Which of the following statements defines a genome? A) the complete set of an organism's polypeptides B) the complete set of a species' polypeptides C) a karyotype D) the complete set of an organism's genes and other DNA sequences

the complete set of an organism's genes and other DNA sequences

What component of amino acid structure varies among different amino acids? A) the long carbon-hydrogen tails of the molecule B) the presence of a central C atom C) the components of the R group D) the glycerol molecule that forms the backbone of the amino acid

the components of the R group

The decline of MPF activity at the end of mitosis is due to A) the destruction of the protein kinase Cdk. B) decreased synthesis of Cdk. C) the degradation of cyclin. D) the accumulation of cyclin.

the degradation of cyclin.

Individuals with the disorder xeroderma pigmentosum are hypersensitive to sunlight, and mutations to the DNA in their skin cells are left uncorrected. Why are the mutations not corrected in individuals with this disorder? A) The disorder makes cells unable to replicate DNA. B) The disorder causes mitosis to stop during metaphase. C) The disorder makes cells unable to form chromosomes. D) The disorder causes cells to be unable to repair thymine dimers.

the disorder causes cells to be unable to REPAIR THYMINE DIMERS

Which of the following illustrations is NOT A STRUCTURAL ISOMER of an organic compound with the molecular formula C6H14? For clarity, only the carbon skeletons are shown; hydrogen atoms that would be attached to the carbons have been omitted.

the double bond

The partial negative charge in a molecule of water occurs because ________. A) the oxygen atom donates an electron to each of the hydrogen atoms B) the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus C) the oxygen atom has two pairs of electrons in its valence shell that are not neutralized by hydrogen atoms D) one of the hydrogen atoms donates an electron to the oxygen atom

the electrons shared between the oxygen and hydrogen atoms SPEND MORE TIME around the oxygen atom nucleus than around the hydrogen atom nucleus

In the term trace element, the adjective trace means that A) the element is required in very small amounts. B) the element can be used as a label to trace atoms through an organism's metabolism. C) the element is very rare on Earth. D) the element enhances health but is not essential for the organism's long-term survival.

the element is required in VERY SMALL amounts

The reactivity of an atom arises from A) the average distance of the outermost electron shell from the nucleus. B) the existence of unpaired electrons in the valence shell. C) the sum of the potential energies of all the electron shells. D) the potential energy of the valence shell.

the existence of unpaired electrons in the valence shell

Which of the following is an example of qualitative data? A) The fish swam in a zigzag motion. B) The contents of the stomach are mixed every 20 seconds. C) The temperature decreased from 20°C to 15°C. D) The six pairs of robins hatched an average of three chicks each.

the fish swam zig zag motion

Which of the following events takes place in the electron transport chain? A) the breakdown of glucose into six carbon dioxide molecules B) the breakdown of an acetyl group to carbon dioxide C) the harnessing of energy from high-energy electrons derived from glycolysis and the citric acid cycle D) substrate-level phosphorylation

the harnessing of energy from high-energy electrons derived from glycolysis and the citric acid cycle

Why are HYDROCARBONS INSOLUBLE in water? A) The majority of their bonds are polar covalent carbon-to-hydrogen linkages. B) The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages. C) They exhibit considerable molecular complexity and diversity. D) They are less dense than water.

the majority of their bonds are NONPOLAR covalent carbon-to-hydrogen linkages

What happens when ELECTRONS ARE PASSED from one atom to a more electronegative atom? A) The more electronegative atom is reduced, and energy is released. B) The more electronegative atom is reduced, and energy is consumed. C) The more electronegative atom is oxidized, and energy is consumed. D) The more electronegative atom is oxidized, and energy is released.

the more electronegative atom is REDUCED and energy is RELEASED

In an RNA sample, ________. A) the number of thiamine may or may not equal the number of adenine B) the number of purine always equals the number of pyrimidine C) the number of thiamine always equals the number of uracil D) the number of purine may or may not equal the number of and pyrimidine

the number of purine may or may not equal the number of and pyrimidine

Which of the following events are associated with CHEMIOSMOSIS in chloroplasts? A) The pH of the stroma increases and ATP is synthesized. B) The pH of the thylakoid space increases and ATP is synthesized. C) The pH of the cytoplasm outside the chloroplast decreases and ATP is synthesized. D) The pH of the stroma decreases and ATP is hydrolyzed.

the pH of the THYLAKOID SPACE increases and ATP is SYNTHESIZED

A beaker contains 100 milliliters (mL) of NaOH solution at pH = 13. A technician carefully pours into the beaker 10 mL of HCl at pH = 1. Which of the following statements correctly describes the result of this mixing? A) The concentration of Na+ ions will rise. B) The pH of the beaker's contents will increase. C) The pH of the beaker's contents will be neutral. D) The pH of the beaker's contents will decrease.

the pH of the beaker's contents will DECREASE

What determines whether a carbon atom's covalent bonds to other atoms are in a TETRAHEDRAL configuration or a PLANAR configuration? A) the presence or absence of bonds with oxygen atoms B) the presence or absence of double bonds between the carbon atom and other atoms C) the polarity of the covalent bonds between carbon and other atoms D) the solvent in which the organic molecule is dissolved

the presence or absence of DOUBLE BONDS

How does the PRIMARY TRANSCRIPT in the nucleus of a EUKARYOTIC cell compare to the functional mRNA? A) the primary transcript is the same size as the mRNA B) the primary transcript is larger than the mRNA C) the primary transcript is smaller than the mRNA D) both the primary transcript and mRNA contain introns

the primary transcript is LARGER than the mRNA

Which of the following statements best describes the addition rule of probability? A) the probability that two or more independent events will occur simultaneously B) the probability that either one of two independent events will occur C) the probability of producing two or more heterozygous offspring D) the likelihood that a trait is due to two or more meiotic events

the probability that either one of two independent events will occur

Independent assortment of chromosomes is a result of which of the following processes? A) the random way each pair of homologous chromosomes lines up at the metaphase plate during meiosis I B) the random combinations of eggs and sperm during fertilization C) the random distribution of the sister chromatids to the two daughter cells during anaphase II D) the diverse combination of alleles that may be found within any given chromosome

the random way each pair of homologous chromosomes lines up at the metaphase plate during meiosis I

Which action could produce a carbonyl group? A) the replacement of the -OH of a carboxyl group with hydrogen B) the addition of a thiol to a hydroxyl C) the addition of a hydroxyl to a phosphate D) the replacement of the nitrogen of an amine with oxygen

the replacement of the -OH of a CARBOXYL group with HYDROGEN

What causes the shape of the molecule shown? A) the shape of the two p orbitals in the carbon atom B) the shape of the one s orbital in the carbon atom C) the shape of the sp3 hybrid orbitals of the electrons shared between the carbon and hydrogen atoms D) hydrogen bonding configurations between the carbon and hydrogen atoms

the shape of the sp3 HYBRID orbitals of the electrons shared between the carbon and hydrogen atoms

Which of the following aspects of enzyme structure is best described by a clasping handshake analogy? A) the specific manner in which an enzyme folds to form secondary and tertiary structures B) the specific manner in which an enzyme interacts with water C) the specific manner in which an enzyme binds substrate D) the specific manner in which an enzyme is denatured by low pH

the specific manner in which an enzyme binds substrate

Which of the following best demonstrates the unity among all organisms? A) emergent properties B) descent with modification C) the structure and function of DNA D) natural selection

the structure and function of DNA

A salamander relies on hydrogen bonding to stick to various surfaces. Therefore, a salamander would have the greatest difficulty clinging to a ________. A) slightly damp surface B) surface of hydrocarbons C) surface of mostly carbon-oxygen bonds D) surface of mostly carbon-nitrogen bonds

the surface of HYDROCARBONS

Some bacteria are metabolically active in hot springs because A) they are able to maintain a lower internal temperature. B) high temperatures make catalysis unnecessary. C) their enzymes have high optimal temperatures. D) their enzymes are completely insensitive to temperature.

their enzymes have high optimal temperatures.

Why are LIPIDS AND PROTEINS FREE to move laterally in membranes? A) The interior of the membrane is filled with liquid water. B) Lipids and proteins repulse each other in the membrane. C) Hydrophilic portions of the lipids are in the interior of the membrane. D) There are only weak hydrophobic interactions in the interior of the membrane.

there are ONLY WEAK HYDROPHOBIC interactions in the interior of the membrane

When a cell is in EQUILIBRIUM with its environment, which of the following processes occurs for substances that can DIFFUSE through the plasma membrane? A) There is directed movement of substances into and out of the cell. B) There is random movement of substances into and out of the cell. C) There is no movement of substances into or out of the cell. D) All movement of molecules across the plasma membrane occurs by active transport.

there is RANDOM movement of substances into and out of the cell

What is the function of the PIGMENT MOLECULES in a LIGHT HARVESTING complex in the thylakoid membranes? A) They split water and release oxygen from the reaction-center chlorophyll. B) They absorb and transfer light energy to the reaction-center chlorophyll. C) They synthesize ATP from ADP and i. D) They transfer electrons to NADP+.

they ABSORB and TRANSFER light energy to the reaciton-center chlorophyll

CAROTENOIDS s are often found in foods that are considered to have antioxidant properties in human nutrition. What related function do they have in plants? A) They serve as accessory pigments to increase light absorption. B) They protect against oxidative damage from excessive light energy. C) They shield the sensitive chromosomes of the plant from harmful ultraviolet radiation. D) They reflect orange light and enhance red light absorption by chlorophyll.

they PROTECT against OXIDATIVE DAMAGE from excessive light energy

Several organisms, primarily PROTISTS, have what are called iINTERMEDIATE MITOTIC ORGANIZATION What is the most probable hypothesis about these intermediate forms of cell division? A) They represent a form of cell reproduction that must have evolved completely separately from those of other organisms. B) They rely on totally different proteins for the processes they undergo. C) They may be more closely related to plant forms that also have unusual mitosis. D) They show some but not all of the evolutionary steps toward complete mitosis.

they SHOW some but not all of the EVOLUTIONARY steps toward complete mitosis

People who are lactose intolerant cannot extract energy from milk because ________. A) they are missing an enzyme B) lactose is too big to be digested by the enzymes C) milk is fermented to a by-product, which cannot be digested D) they are missing the bacteria that can digest lactose

they are missing an enzyme

In what way do KINETOCHORE MICROTUBULES facilitate the process of SPLITTING OF CENTROMERES? A) They use motor proteins to hydrolyze the centromere at specific arginine residues. B) They create tension by pulling toward opposite poles. C) They slide past each other like actin microfilaments. D) They phosphorylate the centromere, thereby changing its conformation.

they create TENSION by pulling towards opposite poles

Which of the following statements correctly describes CIS-TRANS ISOMERS? A) They have variations in arrangement around a double bond. B) They have an asymmetric carbon that makes them mirror images. C) They have the same chemical properties. D) They have different molecular formulas.

they have VARIATIONS in arrangement around DOUBLE BOND

YEAST CELLS of mating type a are genetically engineered to produce only mating factor α instead of the normal mating factor a. The gene for the mating factor receptor was unaltered. How will these engineered cells behave in terms of mating? A) They will only mate with normal mating type a cells. B) They will only mate with normal mating type α cells. C) They will mate with each other or with normal mating type a cells, but not with normal mating type α cells. D) They will only mate each other and not with normal mating type a or α cells.

they will MATE with EACHOTHER or with

A tripeptide has ________. A) three amino acids and two peptide bonds B) three amino acids and three peptide bonds C) two amino acids and three peptide bonds D) four amino acids and three peptide bonds

three amino acids and two peptide bonds

How might a change of one amino acid at a site, distant from the active site of an enzyme, alter the substrate specificity of an enzyme? A) by changing the stability of the enzyme B) by changing the three-dimensional conformation of the enzyme C) by changing the optimum pH for the enzyme D) by changing the binding site for a noncompetitive inhibitor

three-dimensional conformation

A defect in which of the following intercellular junctions would allow partially digested material to leak passively between the cells of the small intestine into the abdominal cavity? A) desmosomes B) gap junctions C) plasmodesmata D) tight junctions

tight junctions

In E. coli, what is the function of DNA polymerase III? A) to unwind the DNA helix during replication B) to seal together the broken ends of DNA strands C) to add nucleotides to the 3' end of a growing DNA strand D) to degrade damaged DNA molecules

to ADD nucleotides to the 3' end of a growing DNA strand

In cats, black fur color is determined by an X-linked allele; the other allele at this locus determines orange color. The heterozygote is tortoiseshell. What kinds of offspring would you expect from the cross of a black female and an orange male? A) tortoiseshell females; tortoiseshell males B) black females; orange males C) tortoiseshell females; black males D) orange females; black males

tortoiseshell females; black males

One possible result of chromosomal breakage is for a fragment to join a nonhomologous chromosome. What is this type of chromosomal alteration called? A) deletion B) inversion C) translocation D) duplication

translocation

Sex determination in mammals is due to the SRY gene found on the Y chromosome. Which of the following situations could allow a person with an XX karyotype to develop a male phenotype? A) the loss of the SRY gene from an autosome B) translocation of SRY to an X chromosome C) the presence of an extra autosomal chromosome D) the presence of one normal and one shortened (deleted) X

translocation of SRY to an X chromosome

What is a primary function of integrins? A) connecting intermediate filaments to microtubules involved in vesicular transport B) linking the primary and secondary cell walls in plants C) transmitting signals from the extracellular matrix to the cytoskeleton D) transmitting chemical signals from the Golgi apparatus to the plasma membrane

transmitting signals from the extracellular matrix to the cytoskeleton

The loss of water from a plant by transpiration cools the leaf. Movement of water in transpiration requires both adhesion to the conducting walls and wood fibers of the plant and cohesion of the molecules to each other. A scientist wanted to increase the rate of transpiration of a crop species to extend its range into warmer climates. The scientist substituted a nonpolar solution with an atomic mass similar to that of water for hydrating the plants. What do you expect the scientist's data will indicate from this experiment? A) The rate of transpiration will be the same for both water and the nonpolar substance. B) The rate of transpiration will be slightly lower with the nonpolar substance as the plant will not have evolved with the nonpolar compound. C) Transpiration rates will fall to zero as nonpolar compounds do not have the properties necessary for adhesion and cohesion. D) Transpiration rates will increase as nonpolar compounds undergo adhesion and cohesion with

transpiration rates will fall to ZERO as nonpolar compounds do not have the properties

Cells require which of the following to form cilia or flagella? A) tubulin B) laminin C) actin D) intermediate filaments

tubulin

How many electron pairs are shared between carbon atoms in a molecule that has the formula C2H4? A) one B) two C) three D) four

two

Somatic cells of roundworms have four individual chromosomes per cell. How many chromosomes would you expect to find in an ovum from a roundworm? A) four B) two C) eight D) a diploid number

two

How is a single covalent bond formed? A) Two atoms share two pairs of electrons. B) Two atoms share two electrons. C) Two atoms share one electron. D) One atom loses a pair of electrons to the other.

two atoms share two electrons

In glycolysis, for each molecule of glucose oxidized to pyruvate, ________. A) two molecules of ATP are used, and two molecules of ATP are produced B) two molecules of ATP are used, and four molecules of ATP are produced C) four molecules of ATP are used, and two molecules of ATP are produced D) two molecules of ATP are used, and six molecules of ATP are produced

two molecules of ATP are used, and four molecules of ATP are produced

DIFFERENCES AMONG ORGANISMS s are caused by differences in the ________. A) elemental composition from organism to organism B) types and relative amounts of organic molecules synthesized by each organism C) sizes of the organic molecules in each organism D) types of inorganic compounds present in each organism

types and RELATIVE AMOUNTS of ORGANIC molecules synthesized by each organism

Systems biology is mainly an attempt to A) analyze genomes from different species. B) simplify complex problems by reducing the system into smaller, less complex units. C) understand the behavior of entire biological systems by studying interactions among its component parts. D) build high-throughput machines for the rapid acquisition of biological data.

understand the behavior of entire biological systems by studying interactions among its component parts

Which of the following will be true when the system illustrated above reaches equilibrium? A) The concentration of sucrose on side A will be greater than the concentration of sucrose on side B. B) The water level will be higher in side A than in side B. C) The water levels will be unchanged. D) The water level will be higher in side B than in side A.

water levels will be higher in side A than side B

Which of the following is a hydrophobic material? A) paper B) table salt C) wax D) sugar

wax

Some photosynthetic organisms contain chloroplasts that lack photosystem II, yet are able to survive. Which of the following approaches would be the best way to DETECT LACK OF PHOTOSYSTEM II in these organisms? A) Determine whether they have thylakoid membranes. B) Determine whether they consume CO2 in the dark. C) Determine whether they produce O2 in the light. D) Determine the action spectrum for photosynthesis in these organisms.

whether they PRODUCE O2 IN LIGHT

Use the following figure to answer the question. The molecule illustrated in the figure ________. A) is a saturated fatty acid B) stores genetic information C) will be liquid at room temperature D) is a carbohydrate

will be liquid at room temperature

The following question refers to the pedigree chart in the figure for a family, some of whose members exhibit the dominant trait, W. Affected individuals are indicated by a dark square or circle. What is the genotype of individual II-5? A) WW B) Ww C) ww D) ww or Ww

If we continue to follow the cell lineage from question 4, then the DNA content of a single cell at metaphase of meiosis II will be A) 0.25x. B) 0.5x. C) x. D) 2x.

You are suffering from Streptococcus throat infection. You share the following with the bacteria that is responsible for your condition. A) You both belong to the same domain. B) You both are made up of cells. C) You both have genetic material in your nucleus. D) You and Streptococcus have nothing in common.

you are both made of cells

Feather color in budgies is determined by two different genes, Y for pigment on the outside of the feather, and B for pigment on the inside of the feather. YYBB, YyBB, or YYBb is green; yyBB or yyBb is blue; YYbb or Yybb is yellow; and yybb is white. Two blue budgies were crossed. Over the years, they produced 22 offspring, five of which were white. What are the most likely genotypes for the two blue budgies? A) yyBB and yyBB B) yyBB and yyBb C) yyBb and yyBb D) yyBb and yybb

yyBb and yyBb

The mathematical expression for the change in free energy of a system is ΔG = ΔH - TΔS. Which of the following statements is correct? A) ΔS is the change in enthalpy, a measure of randomness. B) ΔH is the change in entropy, the energy available to do work. C) ΔG is the change in free energy. D) T is the temperature in degrees Celsius.

BIO 1305 Kang Final ch 1, 2, 3, 4, 5, 6, 7, 8,9,10, 11, 12, 13, 14, 15 16, 17

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