final BIOL 111 CWI

What is a ribozyme?

B) an RNA with enzymatic activity

A series of enzymes catalyze the reaction 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. 74) With respect to the enzyme that converts X to Y, substance A functions as

B) an allosteric inhibitor.

47) 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

B) an endergonic reaction coupled to an exergonic reaction.

32) Polysaccharides, triacylglycerides, and proteins are similar in that they A) are synthesized from monomers by the process of hydrolysis. B) are synthesized from subunits by dehydration reactions. C) are synthesized as a result of peptide bond formation between monomers. D) are decomposed into their subunits by dehydration reactions. E) all contain nitrogen in their monomer building blocks.

B) are synthesized from subunits by dehydration reactions.

In eukaryotes, general transcription factors

B) bind to other proteins or to a sequence element within the promoter called the TATA box.

68) When skeletal muscle cells undergo anaerobic respiration, they become fatigued and painful. This is now known to be caused by

B) buildup of lactate.

46) How does a noncompetitive inhibitor decrease the rate of an enzyme reaction?

B) by changing the shape of the enzyme's active site

Alternative RNA splicing

B) can allow the production of proteins of different sizes from a single mRNA.

Which of the following sequences correctly represents the flow of electrons during photosynthesis?

H2O->NADPH->Calvin Cycle

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?

HT.

Unsaturated fatty Acids

Have one or more double bonds. Forms bent chains. Results in liquid form and found in plants and fish.

Saturated Fatty Acids

Have the maximum number of hydrogen atoms possible and no double bonds. Straight chains. Results in solids and found in animals.

Kingdoms

High-level classification of organisms distinguished partly by their modes of nutrition.

Mendel was able to draw his ideas of segregation and independent assortment because of the influence of which of the following?

His reading of the scientific literature current in the field.

Thomas Hunt Morgan's choice of Drosophila melanogaster has been proven to be useful even today. Which of the following has/have continued to make it a most useful species?

I. its four pairs of chromosomes II. a very large number of visible as well as biochemically mutant phenotypes III. easy and inexpensive maintenance IV. short generation time and large number of offspring

Sister chromatids are genetically ______ & are joined at the ______

Identical Centromere

Cholesterol

Important steroid which is a common component in animal cell membranes that allows for fluidity of membranes. Building block for other steroids including hormones.

Which of the following provides an example of epistasis?

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

Carbohydrates

Include sugars and polymers of sugars. (Monosaccharides, Disaccharides, and Polysaccharides)

3 mechanisms contribute to genetic variation

Independent assortment of chromosomes Crossing over Random fertilization

Sickle-cell disease

Inherited blood disorder, results from a single amino acid substitution in the protein hemoglobin

Sexual Reproduction

Involves gametes

Types of Energy

Kinetic, potential, chemical

D) as a disaccharide Hint: The question asks about two molecules (monomers) joined together through a glycosidic linkage. Two sugar monomers joined together is a di-saccharide

Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified? A) as a pentose B) as a hexose C) as a monosaccharide D) as a disaccharide E) as a polysaccharide

Macromolecules

Large molecules composed of thousands of covalently connected atoms

Polymers

Long molecules consisting of many similar building blocks

Variance

Measures how much difference, or variation, there is between the values you have obtained. The smaller the variance, the closer the values will be to the mean.

Deviation

Measures how the measurements vary from the mean (+ or -). In other words, what is the difference between an actual measurement and the mean, or average, of the sample?

Sexual reproduction examples

Meiosis (occurs in gonads to produce gametes)

After chromosomes duplicate, two divisions follow

Meiosis l (reductional division) 2 haploid daughter cells with replicated chromosomes Meiosis ll (equational division) sister chromatids separate

Meiosis takes place in two sets of cell divisions called

Meiosis l and meiosis ll

Which of the following is the meaning of the chromosome theory of inheritance as expressed in the early 20th century?

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

Genomic imprinting is generally due to the addition of methyl (-CH3) groups to C nucleotides in order to silence a given gene. If this depends on the sex of the parent who transmits the gene, which of the following must be true?

Methylation must be reversible in ovarian and testicular cells

The original source of genetic diversity

Mutations (Changes in an organism's DNA)

Why does recombination between linked genes continue to occur?

New allele combinations are acted upon by natural selection

Down syndrome has a frequency in the U.S. population of ~1/700 live births. In which of the following groups would you expect this frequency to be significantly higher?

No groups have such higher frequency

Polynucleotides

Nucleic acids that are polymers

If photosynthesizing green algae are provided with CO2 synthesized with heavy oxygen (18O), later analysis will show that all but one of the following compounds produced by the algae contain the 18O label. That one is

O2

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?

One member of the couple underwent nondisjunction in gamete production

Why did the F1 offspring of Mendel's classic pea cross always look like one of the two parental varieties?

One phenotype was completely dominant over another.

Properties of Life

Order, Evolutionary Adaptation, Response to the Environment, Regulation, Energy Processing, Growth and Development, Reproduction.

Free Ribosomes

Organelles that function in protein synthesis.

Amino Acids

Organic molecules with carboxyl and amino groups. Differing side chains (R groups)

Consumers

Organisms that feed on producers and other consumers.

Natural Selection

Organisms with the desired trait will reproduce more successfully than organisms without the trait. Changes occur in DNA (mutation) to create the desired trait.

Heterotroph

Other-feeder

Some photosynthetic bacteria (e.g., purple sulfur bacteria) have photosystem I but not II, while others (e.g. cyanobacteria) have both PSI and PSII. Which of the following might this observation imply?

Photosystem I must be more ancestral

Producers

Plants and other photosynthetic organisms.

Which of the following describes the ability of a single gene to have multiple phenotypic effects?

Pleiotropy.

Polysaccharides

Polymers of sugars, have storage and structural roles determined by its sugar monomers and the positions of glycosidic linkages.

Nucleotides

Polynucleotides made of monomers consisting of a nitrogenous base, a pentose sugar and one or more phosphate groups are called...

Cellulose

Polysaccharide that is a major component of the tough wall of plant cells. Alpha & Beta glucose rings.

Carbohydrate Macromolecules

Polysaccharides, which are polymers composed of many sugar building blocks

The structural level of a protein least affected by a disruption and hydrogen bonding is the

Primary level

Base pairing

Principle that bonds in DNA can form only between adenine and thymine and between guanine and cytosine

Scientific Method

Prior Knowledge Observations Questions Hypothesis Prediction Experiment Conclusion/Analysis

Gene expression

Process by which a gene produces its product and the product carries out its function.

What is the greatest benefit of having used a testcross for this experiment?

Progeny can be scored by their phenotypes alone

Division in meiosis l occurs in 4 phases

Prophase Metaphase Anaphase Telophase & Cytokinesis

Crossing over begins very early is what phase?

Prophase l

Chaperonins

Protein molecules that assist the proper folding of other proteins.

Crossing over produces __________, which combine DNA inherited from each parent

Recombinant chromosomes

Plasma membrane

Regulates and controls what goes in and out of the cell

"Quaternary" structure of protein

Results when two or more polypeptide chains form one macromolecule. (Collogen: 3 polypeptides & Hemoglobin: 4 polypeptides)

In cattle, roan coat color occurs in the heterozygous offspring of red and white homozygotes. Which of the following crosses would produce offspring in the ratio of 1 red:2 roan:1 white?

Roan x roan.

X-ray crystallography

Scientists use this to determine a protein's structure. Another method is NMR

Enzymatic Proteins

Selective acceleration of chemical reactions (digestive)

Autotroph

Self-feeder

Cytokinesis

Separates the cytoplasm

Gametes

Sex cells. Male: sperm. Female: ova.

Example of evolutionary adaptation

Sickle cell mutation - one gene provides malaria resistance, both genes creates sickle cell anemia.

Metaphase ll

Sister chromatids are arranged at the metaphase plate Sister chromatids are no longer identical

Anaphase ll

Sister chromatids separate Sister chromatids of each chromosome now move as two newly individual chromosomes toward opposite poles

Which of the following is an example of polygenic inheritance?

Skin pigmentation in humans.

Monomers

Small repeating units that serve as building blocks for polymers

An inversion in a human chromosome often results in no demonstrable phenotypic effect in the individual. What else may occur?

Some abnormal gametes may be formed

Enzymes

Specialized macromolecules that act as a catalyst to speed up chemical reactions such as dehydration reactions and hydrolysis

Standard Deviation

Standard deviation gives you an idea of how widely spread your values are about the mean. Smaller = closer values to the average. (Picture a tall, thin, bell-shaped curve. Larger - wide bell curve.)

Null Hypothesis

States that there is no significant difference between specified populations, any observed difference being due to sampling or experimental error.

Chitin

Structural Polysaccharide found in exoskeleton of arthhropods. Provides structural support of cell walls of many fungi.

Classic Experimental Design

Test Population (100 identical rats) Experimental Group (given DDT in food) Controlled Group (no DDT, everything else constant) Independent Variable (under study, manipulated & changing) Dependent Variable (variable that changes based on independent variable) Controlled variables (water, amt. of food, everything not manipulated)

Two plants are crossed, resulting in offspring with a 3:1 ratio for a particular trait. What does this suggest?

That the parents were both heterozygous for a single trait.

Community

The array of organisms inhabiting a particular ecosystem.

Cell

The basic unit of life that retains the properties of life.

Which of the following statements is true of linkage?

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

Cytoplasm

The contents of the cell bounded by the plasma membrane; in eukaryotes, the portion of the cell outside the nucleus.

Range

The difference between the smallest and the largest measurements. R = Max - Min

Eukarya

The domain that includes Kingdoms Plantae, Animalia, and Fungi.

Archaea

The domain that includes prokaryotes that live in Earth's most extreme environments.

Bacteria (Domain)

The domain that includes prokaryotes which are the most diverse and widespread of all kingdoms.

E) monosaccharides.

The element nitrogen is present in all of the following except A) proteins. B) nucleic acids. C) amino acids. D) DNA. E) monosaccharides.

Independent Variable

The experimental factor that is manipulated; the variable whose effect is being studied.

Three genes at three loci are being mapped in a particular species. Each has two phenotypes, one of which is markedly different from the wild type. The unusual allele of the first gene is inherited with either of the others about 50% of the time. However, the unusual alleles of the other two genes are inherited together 14.4% of the time. Which of the following describes what is happening?

The first gene is assorting independently from the other two that are linked

Map units on a linkage map cannot be relied upon to calculate physical distances on a chromosome for which of the following reasons?

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?

The gene involved is on the X chromosome

Control

The group in an experiment which is used as a standard for comparison.

Domains

The highest level of classification of living organisms. Eukarya, Archaea, Bacteria

Which of the following differentiates between independent assortment and segregation?

The law of independent assortment requires describing two or more genes relative to one another.

Which of the following statements best represents the relationships between the light reactions and the Calvin cycle?

The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, Pi, and NADP+ to the light reactions

Denaturation

The loss of a protein's native structure caused by alterations in pH, salt concentration, temperature etc...

Independent assortment of chromosomes

The number of combinations possible when chromosomes assort independently into gametes is 2n, where n is the haploid number of the organism. If n = 3, there are 2^3 = 8 possible combinations. For humans with n = 23, there are 2^23, or more than 8 million *only if both parental genes are different

Dependent Variable

The outcome factor; the variable that may change in response to manipulations of the independent variable.

Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes

The phospodiester linkages of the polynucleotide backbone would be broken

Nucleoside

The portion of a nucleotide without the phosphate group is called...

Which of the following is the best statement of the use of the addition rule of probability?

The probability that either one of two independent events will occur.

An ideal procedure for fetal testing in humans would have which of the following features?

The procedure that can be performed at the earliest time in the pregnancy.

Taxonomy

The science of classification and nomenclature (naming)

Genetics

The scientific study of heredity and variation

Inquiry

The search for information and explanation, often focusing on specific questions.

Monosaccharides

The simplest carbohydrate, or single sugars. Molecular formulas that are usually multiples of CnH2nOn. Classified by their location of the carbonyl group (aldose or ketos) & number of carbons in the carbon skeleton

Ecology

The study of organisms in their physical and chemical environment

Heredity

The transmission of traits from one generation to the next

How would one explain a testcross involving F1 dihybrid flies in which more parental-type

The two genes are closely linked on the same chromosome

What does a frequency of recombination of 50% indicate?

The two genes are likely to be located on different chromosomes

Phosphate-Deoxyribose

The two molecules that when added to A, T, G, or C make up a nucleotide

Fertilization (syngamy)

The union of gametes (The sperm and the egg)

Median

The value that is in the middle of a group of measurements.

Most genes have many more than two alleles. However, which of the following is also true?

There may still be only 2 phenotypes for the trait.

Nucleic Acids

These store, transmit, and help express hereditary information.

What is the reason that linked genes are inherited together?

They are located close together on the same chromosome

Generation of proton gradients across membranes occurs during

both photosynthesis and respiration

Synthesis of ATP by the chemiosmotic mechanism occurs during

both photosynthesis and respiration

endoplasmic reticulum (ER)

internal membrane system in which components of cell membrane and some proteins are constructed

16) All of the following are polysaccharides except A) lactose. B) glycogen. C) chitin. D) cellulose. E) amylopectin.

lactose

At which phase(s) is it preferable to obtain chromosomes to prepare a karyotype?

late prophase or metaphase

If plant gene alterations cause the plants to be deficient in photorespiration, what would most probably occur?

less ATP would be generated

Which of the events listed below occur in the light reactions of photosynthesis

light is absorbed and funneled to reaction-center chlorophyll a

Produces NADH

light reactions alone

Produces molecular oxygen (O2)

light reactions alone

Steroids

lipids characterized by a carbon skeleton consisting of four fused rings

light microscopy

magnification of cellular structures up to 1000 X

Males are more often affected by sex-linked traits than females because

males are hemizygous for the X chromosome

central vacuole

membranous sac in plant cells with roles in reproduction, growth, and storage

Homologous pairs of chromosomes orient randomly at

metaphase l of meiosis

cytoskeleton

microscopic network of protein fibers within cytoplasm that gives shape to cell

mitotic spindle

microtubules that attach to centromeres through kinetochore proteins of chromosomes and pull sister chromatids apart during cell divisions

The pedigree in Figure 15.3 shows the transmission of a trait in a particular family. Based on this pattern of transmission, the trait is most likely

mitochondria

Evolutionary Adaptation

natural selection or "survival of the fittest."

The splitting of carbon dioxide to form oxygen gas and carbon compounds occurs during

neither photosynthesis nor respiration

Requires glucose

neither the light reactions nor the Calvin cycle

nuclear lamina

netlike array of intermediate filaments that maintains shape of nucleus

What is the source of the extra chromosome 21 in an individual with Down syndrome?

nondisjunction or translocation in either parent

A man who is an achondroplastic dwarf with normal vision marries a color-blind woman of normal height. The man's father was 6 feet tall, and both the woman's parents were of average height. Achondroplastic dwarfism is autosomal dominant, and red-green color blindness is X-linked recessive. How many of their daughters might be expected to be color-blind dwarfs?

none

A woman is found to have 47 chromosomes, including three X chromosomes. Which of the following describes her expected phenotype?

normal female

Emergent Properties

novel properties that appear at higher levels of organization due to the interaction of individual components (ex: cake ingredients become batter become cake, and each stage has different properties tho made up of the same things)

In thylakoids, protons travel through ATP synthase from the stroma to the thylakoid space. Therefore the catalytic "knobs" of ATP synthase would be located

on the stroma side of the membrane

Human males have what specific chromosomes

one X and one Y chromosome

Each pair of homologous chromosomes includes

one chromosome from each parent

Meiosis results in

one set of chromosomes in each gamete 23 single chromosomes only occurs in gametes

A karyotype

ordered display of the pairs of chromosomes from a cell

rough ER

organelle continuoues with nuclear membrane, to which ribosomes are tethered and proteins are synthesized for export

lysosome

organelle filled with enzymes that break down chemicals

mitochondria

organelle in all eukaryotic cells where chemical energy in glucose and fats is transformed into ATP (cellular respiration SITE)

chloroplast

organelle in plants where sunlight energy is used to synthesize glucose (photosynthesis SITE)

nucleus

organelle that contains DNA and controls processes of cell

smooth ER

organelle where lipids are synthesized

nucleolus

organelle where ribosomes are synthesized and partially assembled (within nucleus)

centrioles

organelles in animal cells from which mitotic spindle forms during cell division (resemble basal bodies)

ribosomes

organelles made of protein and rRNA that direct protein synthesis (in cytoplasm or tethered to rough ER)

In mechanism, photophosphorylation is most similar to

oxidative phosphorylation in cellular respiration

Chromosomes

packaged DNA

Anaphase l

pairs of homologous chromosomes separate Sister chromatids remain attached at the centromere

homologous or homologs

pairs of sister chromatids each pair comes from maternal and parental genes

nuclear envelope

perforated double membrane that controls flow of materials (around nucleus)

Reduction of NADP+ occurs during

photosynthesis

In humans, the embryonic and fetal forms of hemoglobin have a higher affinity for oxygen than that of adults. This is due to

A) nonidentical genes that produce different versions of globins during development.

Which of the following mechanisms is (are) used to coordinately control the expression of multiple, related genes in eukaryotic cells?

A) organization of the genes into clusters, with local chromatin structures influencing the expression of all the genes at once

104) The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is

A) oxygen.

60) One possible use of transgenic plants is in the production of human proteins, such as vaccines. Which of the following is a possible hindrance that must be overcome? A) prevention of transmission of plant allergens to the vaccine recipients B) prevention of vaccine-containing plants being consumed by insects C) use of plant cells to translate non-plant derived mRNA D) inability of the human digestive system to accept plant-derived protein E) the need to cook all such plants before consuming them

A) prevention of transmission of plant allergens to the vaccine recipients

Cell differentiation always involves the

A) production of tissue-specific proteins, such as muscle actin.

13) The DNA fragments making up a genomic library are generally contained in A) recombinant plasmids of bacteria. B) recombinant viral RNA. C) individual wells. D) DNA-RNA hybrids E) radioactive eukaryotic cells

A) recombinant plasmids of bacteria.

41) A researcher has used in vitro mutagenesis to mutate a cloned gene and then has reinserted this into a cell. In order to have the mutated sequence disable the function of the gene, what must then occur? A) recombination resulting in replacement of the wild type with the mutated gene B) use of a microarray to verify continued expression of the original gene C) replication of the cloned gene using a bacterial plasmid D) transcription of the cloned gene using a BAC E) attachment of the mutated gene to an existing mRNA to be translated

A) recombination resulting in replacement of the wild type with the mutated gene

61) In alcohol fermentation, NAD+ is regenerated from NADH by

A) reduction of acetaldehyde to ethanol (ethyl alcohol).

The cancer-causing forms of the Ras protein are involved in which of the following processes?

A) relaying a signal from a growth factor receptor

31) The bonding of two amino acid molecules to form a larger molecule requires which of the following? A) removal of a water molecule B) addition of a water molecule C) formation of a glycosidic bond D) formation of a hydrogen bond E) both removal of a water molecule and formation of a hydrogen bond

A) removal of a water molecule

32) RFLP analysis can be used to distinguish between alleles based on differences in which of the following? A) restriction enzyme recognition sites between the alleles B) the amount of DNA amplified from the alleles during PCR C) the ability of the alleles to be replicated in bacterial cells D) the proteins expressed from the alleles

A) restriction enzyme recognition sites between the alleles

26) Which of the following cuts DNA molecules at specific locations? A) restriction enzymes B) gene cloning C) DNA ligase D) gel electrophoresis E) reverse transcriptase

A) restriction enzymes

10) The ATP made during glycolysis is generated by

A) substrate-level phosphorylation.

Which of the following is established prior to fertilization in Drosophila eggs?

A) the anterior-posterior and dorsal-ventral axes

The product of the bicoid gene in Drosophila provides essential information about

A) the anterior-posterior axis.

51) Protein kinases are enzymes that catalyze phosphorylation of target proteins at specific sites, whereas protein phosphatases catalyze removal of phosphate(s) from phosphorylated proteins. Phosphorylation and dephosphorylation can function as an on-off switch for a protein's activity, most likely through

A) the change in a protein's charge leading to a conformational change.

What does the operon model attempt to explain?

A) the coordinated control of gene expression in bacteria

The TATA sequence is found only several nucleotides away from the start site of transcription. This most probably relates to which of the following?

A) the number of hydrogen bonds between A and T in DNA

9) Bacteria that do not take up any plasmids would grow on which media? A) the nutrient broth only B) the nutrient broth and the tetracycline broth C) the nutrient broth and the ampicillin broth D) the tetracycline broth and the ampicillin broth E) all four broths

A) the nutrient broth only

29) The bonding of two amino acid molecules to form a larger molecule requires A) the release of a water molecule. B) the release of a carbon dioxide molecule. C) the addition of a nitrogen atom. D) the addition of a water molecule. E) the release of a nitrous oxide molecule.

A) the release of a water molecule.

17) Which of the following is true of both starch and cellulose? A) They are both polymers of glucose. B) They are cis-trans isomers of each other. C) They can both be digested by humans. D) They are both used for energy storage in plants. E) They are both structural components of the plant cell wall.

A) they are both polymers of glucose

31) DNA fragments from a gel are transferred to a nitrocellulose paper during the procedure called Southern blotting. What is the purpose of transferring the DNA from a gel to a nitrocellulose paper? A) to attach the DNA fragments to a permanent substrate B) to separate the two complementary DNA strands C) to transfer only the DNA that is of interest D) to prepare the DNA for digestion with restriction enzymes E) to separate out the PCRs

A) to attach the DNA fragments to a permanent substrate

In both eukaryotes and prokaryotes, gene expression is primarily regulated at the level of

A) transcription.

The functioning of enhancers is an example of

A) transcriptional control of gene expression.

Which of the following variations on translation would be most disadvantageous for a cell?

A) translating polypeptides directly from DNA

27) How many carbon atoms are fed into the citric acid cycle as a result of the oxidation of one molecule of pyruvate?

A) two

100) These inside-out membrane vesicles

A) will become acidic inside the vesicles when NADH is added.

The light reactions of photosynthesis supply the Calvin cycle with

ATP and NADPH

What are the products of linear photophosphorlyation?

ATP and NADPH

What are the products of the light reactions that are subsequently used by the Calvin Cycle?

ATP and NADPH

Which of the following products of the light reactions of photosynthesis that are utilized in the Calvin Cycle?

ATP and NADPH

ATP

Adenosine tri-phosphate - the molecule that cells recognize and tap into for energy in the brain, muscles, etc. ATP releases energy for cellular work, such as respiration, reproduction, etc.

Mendel's second law of independent assortment has its basis in which of the following events of meiosis I?

Alignment of tetrads at the equator.

B) cholesterol HINT: Anything ending in -'ol' is a lipid / fat, thus a different macromolecule than amino acid.

All of the following contain amino acids except A) hemoglobin. B) cholesterol. C) antibodies. D) enzymes. E) insulin.

The fact that all seven of the pea plant traits studied by Mendel obeyed the principle of independent assortment most probably indicates which of the following?

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

Suppose that a gene on human chromosome 18 can be imprinted in a given pattern in a female parent but not in a male parent. A couple in whom each maternal meiosis is followed by imprinting of this gene have children. What can we expect as a likely outcome?

All the children will bear their mother's imprinting pattern but only daughters will then pass it down

Ecosystem

All the living things in a particular area, along with all the nonliving components of the environment with which life interacts.

Population

All the members of one species in a particular ecosystem.

Peptide Bonds

Amino acids are linked by these causing dehydration reaction

Triacylglycerol

An ester derived from glycerol and three fatty acids

Mendel's observation of the segregation of alleles in gamete formation has its basis in which of the following phases of cell division?

Anaphase I of meiosis.

Why does random fertilization add to genetic variation?

Any sperm can fuse with any ovum (unfertilized egg)

Two forms of Cellular Reproduction

Asexual & sexual

haploid gametes

At sexual maturity, germ line cells in the ovaries and testes produce

The remaining 22 pairs of chromosomes are called

Autosomes

Mean

Average of a group of measurements

101) Which class of biological polymer has the greatest functional variety? A) polysaccharides B) proteins C) DNA D) RNA

B

105) Which of the following statements concerning unsaturated fats is true? A) They are more common in animals than in plants. B) They have double bonds in the carbon chains of their fatty acids. C) They generally solidify at room temperature. D) They contain more hydrogen than do saturated fats having the same number of carbon atoms. E) They have fewer fatty acid molecules per fat molecule.

B

107) Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes? A) The two strands of the double helix would separate. B) The phosphodiester linkages of the polynucleotide backbone would be broken. C) The purines would be separated from the deoxyribose sugars. D) The pyrimidines would be separated from the deoxyribose sugars. E) All bases would be separated from the deoxyribose sugars

B

11) When T2 phages infect bacteria and make more viruses in the presence of radioactive sulfur, what is the result? A) The viral DNA will be radioactive. B) The viral proteins will be radioactive. C) The bacterial DNA will be radioactive. D) both A and B E) both A and C

B

2) In his transformation experiments, what did Griffith observe? A) Mutant mice were resistant to bacterial infections.43 B) Mixing a heat-killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living cells into the pathogenic form. C) Mixing a heat-killed nonpathogenic strain of bacteria with a living pathogenic strain makes the pathogenic strain nonpathogenic. D) Infecting mice with nonpathogenic strains of bacteria makes them resistant to pathogenic strains. E) Mice infected with a pathogenic strain of bacteria can spread the infection to other mice.

B

19) When glucose monomers are joined together by glycosidic linkages to form a cellulose polymer, the changes in free energy, total energy, and entropy are as follows:

B) +ΔG, +ΔH, -ΔS.

35) 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?

B) -20 kcal/mol

19) Starting with one molecule of glucose, the energy-containing products of glycolysis are

B) 2 NADH, 2 pyruvate, and 2 ATP.

88) For each mole of glucose (C6H12O6) oxidized by cellular respiration, how many moles of CO2 are released in the citric acid cycle (see Figure 9.2)?

B) 4

Allolactose induces the synthesis of the enzyme lactase. An E. coli cell is presented for the first time with the sugar lactose (containing allolactose) as a potential food source. Which of the following occurs when the lactose enters the cell?

B) Allolactose binds to the repressor protein.

81) Which step in Figure 9.1 shows a split of one molecule into two smaller molecules?

B) B

Use Figure 20.3 to answer the following questions. The DNA profiles below represent four different individuals. 49) Which of the following statements is consistent with the results? A) B is the child of A and C. B) C is the child of A and B. C) D is the child of B and C. D) A is the child of B and C. E) A is the child of C and D.

B) C is the child of A and B.

11) 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) C18H10O15 E) C3H6O3

B) C18H32O16

77) Which of the following metabolic processes can occur without a net influx of energy from some other process?

B) C6H12O6 + 6 O2 → 6 CO2 + 6 H2O

46) Reproductive cloning of human embryos is generally considered unethical. However, on the subject of therapeutic cloning there is a wider divergence of opinion. Which of the following is a likely explanation? A) Use of adult stem cells is likely to produce more cell types than use of embryonic stem cells. B) Cloning to produce embryonic stem cells may lead to great medical benefits for many. C) Cloning to produce stem cells relies on a different initial procedure than reproductive cloning. D) A clone that lives until the blastocyst stage does not yet have human DNA. E) No embryos would be destroyed in the process of therapeutic cloning.

B) Cloning to produce embryonic stem cells may lead to great medical benefits for many.

Which of these would decrease the entropy within a system?

B) Condensation reaction

50) Which of the following statements is most likely true? A) D is the child of A and C. B) D is the child of A and B. C) D is the child of B and C. D) A is the child of C and D. E) B is the child of A and C.

B) D is the child of A and B.

Which component is not directly involved in translation? E) GTP

B) DNA

93) Which of the following most accurately describes what is happening along the electron transport chain in Figure 9.3?

B) Each electron carrier alternates between being reduced and being oxidized.

4) Why does the oxidation of organic compounds by molecular oxygen to produce CO2 and water release free energy?

B) Electrons are being moved from atoms that have a lower affinity for electrons (such as C) to atoms with a higher affinity for electrons (such as O).

34) Which of the following statements regarding enzymes is true?

B) Enzymes increase the rate of a reaction by lowering the activation energy barrier.

Which of the following statements regarding enzymes is FALSE?

B) Enzymes provide activation energy for the reactions they catalyze

Which of the types of energy listed below can best be described as the portion of energy that is available to do work?

B) Free energy

What is the function of the release factor (RF)?

B) It binds to the stop codon in the A site in place of a tRNA.

Which of the following is a function of a poly-A signal sequence?

B) It codes for a sequence in eukaryotic transcripts that signals enzymatic cleavage ~1035 nucleotides away.

65) Why is glycolysis considered to be one of the first metabolic pathways to have evolved?

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

RNA polymerase in a prokaryote is composed of several subunits. Most of these subunits are the same for the transcription of any gene, but one, known as sigma, varies considerably. Which of the following is the most probable advantage for the organism of such sigma switching?

B) It might allow the polymerase to recognize different promoters under certain environmental conditions.

23) Why is ATP an important molecule in metabolism?

B) It provides energy coupling between exergonic and endergonic reactions.

5) Which of these classes of biological molecules consist of both small molecules and macromolecular polymers? A) lipids B) carbohydrates C) proteins D) nucleic acids E) lipids, carbohydrates, proteins, and nucleic acids all consist of only macromolecular polymers

B) carbohydrates

79) During intense exercise, as skeletal muscle cells go into anaerobiosis, the human body will increase its catabolism of

B) carbohydrates only.

1) What is the term for metabolic pathways that release stored energy by breaking down complex molecules?

B) catabolic pathways

28) All of the following contain amino acids except A) hemoglobin. B) cholesterol. C) antibodies. D) enzymes. E) insulin.

B) cholesterol

67) When skeletal muscle cells are oxygen-deprived, the heart still pumps. What must the heart muscle cells be able to do?

B) continue aerobic metabolism when skeletal muscle cannot

The product of the bicoid gene in Drosophila could be considered a(n)

B) cytoplasmic determinant.

A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. In one set of experiments using this procedure in Drosophila, she was readily successful in increasing phosphorylation of amino acids adjacent to methylated amino acids in histone tails. Which of the following results would she most likely see?

B) decreased chromatin concentration

21) To introduce a particular piece of DNA into an animal cell, such as that of a mouse, you would find more probable success with which of the following methods? A) the shotgun approach B) electroporation followed by recombination C) introducing a plasmid into the cell D) infecting the mouse cell with a Ti plasmid E) transcription and translation

B) electroporation followed by recombination

75) Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as ________ is to ________.

B) exergonic; endergonic

21) A molecule with the formula C18H36O2 is probably a A) carbohydrate. B) fatty acid. C) protein. D) nucleic acid. E) hydrocarbon.

B) fatty acid.

47) The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is most precisely described as

B) feedback inhibition.

30) During aerobic respiration, electrons travel downhill in which sequence?

B) food → NADH → electron transport chain → oxygen

23) Which of the following produces multiple identical copies of a gene for basic research or for large-scale production of a gene product? A) restriction enzymes B) gene cloning C) DNA ligase D) gel electrophoresis E) reverse transcriptase

B) gene cloning

In colorectal cancer, several genes must be mutated in order to make a cell a cancer cell, supporting Knudsenʹs hypothesis. Which of the following kinds of genes would you expect to be mutated?

B) genes involved in control of the cell cycle

12) Which process in eukaryotic cells will proceed normally whether oxygen (O2) is present or absent?

B) glycolysis

54) Genetically engineered plants A) are more difficult to engineer than animals. B) include a transgenic rice plant that can help prevent vitamin A deficiency. C) are being rapidly developed, but traditional plant breeding programs are still the only method used to develop new plants. D) are able to fix nitrogen themselves. E) are banned throughout the world.

B) include a transgenic rice plant that can help prevent vitamin A deficiency.

When this is taken up by the cell, it binds to the repressor so that the repressor no longer binds to the operator:

B) inducer

The MyoD protein

B) is a transcription factor that binds to and activates the transcription of muscle-related genes.

36) The active site of an enzyme is the region that

B) is involved in the catalytic reaction of the enzyme.

52) Besides turning enzymes on or off, what other means does a cell use to control enzymatic activity?

B) localization of enzymes into specific organelles or membranes

2) The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction

B) loses electrons and loses potential energy.

28) Carbon dioxide (CO2) is released during which of the following stages of cellular respiration?

B) oxidation of pyruvate to acetyl CoA and the citric acid cycle

43) It is possible to prepare vesicles from portions of the inner mitochondrial membrane. Which one of the following processes could still be carried on by this isolated inner membrane?

B) oxidative phosphorylation

The process of translation, whether in prokaryotes or eukaryotes, requires tRNAs, amino acids, ribosomal subunits, and which of the following?

B) polypeptide factors plus GTP

A mutant bacterial cell has a defective aminoacyl synthetase that attaches a lysine to tRNAs with the anticodon AAA instead of the normal phenylalanine. The consequence of this for the cell will be that

B) proteins in the cell will include lysine instead of phenylalanine at amino acid positions specified by the codon UUU.

Which of the following experimental procedures is most likely to hasten mRNA degradation in a eukaryotic cell?

B) removal of the 5ʹ cap

Gap genes and pair-rule genes fall into this category:

B) segmentation genes

These genes map out the basic subdivisions along the anterior-posterior axis of the Drosophila embryo:

B) segmentation genes

35) Dideoxyribonucleotide chain-termination is a method of A) cloning DNA. B) sequencing DNA.

B) sequencing DNA.

In eukaryotic cells, transcription cannot begin until

B) several transcription factors have bound to the promoter.

13) An electron loses potential energy when it

B) shifts to a more electronegative atom.

Transcription of the structural genes in an inducible operon

B) starts when the pathwayʹs substrate is present.

59) The ATP made during fermentation is generated by which of the following?

B) substrate-level phosphorylation

107) Most CO2 from catabolism is released during

B) the citric acid cycle.

50) What is proton-motive force?

B) the force exerted on a proton by a transmembrane proton concentration gradient

21) Which of the following best describes enthalpy (H)?

B) the heat content of a chemical system

What is considered to be the first evidence of differentiation in the cells of an embryo?

B) the occurrence of mRNAs for the production of tissue-specific proteins

Within a cell, the amount of protein made using a given mRNA molecule depends partly on

B) the rate at which the mRNA is degraded.

There are 61 mRNA codons that specify an amino acid, but only 45 tRNAs. This is best explained by the fact that

B) the rules for base pairing between the third base of a codon and tRNA are flexible.

27) Why are human sex hormones considered to be lipids? A) They are essential components of cell membranes. B) They are not soluble in water. C) They are made of fatty acids. D) They are hydrophilic compounds. E) They contribute to atherosclerosis.

B) they are not soluble in water

40) RNAi methodology uses double-stranded pieces of RNA to trigger a breakdown or blocking of mRNA. For which of the following might it more possibly be useful? A) to raise the rate of production of a needed digestive enzyme B) to decrease the production from a harmful gain-of-function mutated gene C) to destroy an unwanted allele in a homozygous individual D) to form a knockout organism that will not pass the deleted sequence to its progeny E) to raise the concentration of a desired protein

B) to decrease the production from a harmful gain-of-function mutated gene

In the transcription event of the previous DNA, where would the promoter be located?

B) to the right of the template strand

20) In glycolysis, for each molecule of glucose oxidized to pyruvate

B) two molecules of ATP are used and four molecules of ATP are produced.

4) In animal metabolism, most of the monomers released by digestion of food macromolecules are metabolized to provide energy. Only a small portion of these monomers are used for synthesis of new macromolecules. The net result is that A) water is generated by animal metabolism. B) water is consumed by animal metabolism. C) the water consumed is exactly balanced by the water generated, to maintain homeostasis. D) water is consumed during homeostasis, but water is generated during periods of growth. E) water is generated during homeostasis, but water is consumed during periods of growth.

B) water is consumed by animal metabolism.

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. What did Engelmann conclude about the congregation of bacteria in the red and blue areas?

Bacteria congregated in these areas because these areas had the most oxygen being released

Asexual reproduction examples

Binary fission (bacteria), mitosis (humans, cats, dogs, plants)

Proteins

Biologically functional molecule that consists of one or more polypeptides. They account for more than 50% of the dry mass of most cells.

Nucleotides

Building blocks of nucleic acids

1) For a couple of decades, biologists knew the nucleus contained DNA and proteins. The prevailing opinion was that the genetic material was proteins, and not DNA. The reason for this belief was that proteins are more complex than DNA. What was the basis of this thinking? A) Proteins have a greater variety of three-dimensional forms than does DNA. B) Proteins have two different levels of structural organization; DNA has four. C) Proteins are made of 40 amino acids and DNA is made of four nucleotides. D) Some viruses only transmit proteins. E) A and B are correct.

C

108) The molecular formula for glucose is C6H12O6. What would be the molecular formula for a polymer made by linking ten glucose molecules together by dehydration reactions? A) C60H120O60 B) C6H12O6 C) C60H102O51 D) C60H100O50 E) C60H111O51

C

13) Chargaff's analysis of the relative base composition of DNA was significant because he was able to show that A) the relative proportion of each of the four bases differs within individuals of a species. B) the human genome is more complex than that of other species. C) the amount of A is always equivalent to T, and C to G. D) the amount of ribose is always equivalent to deoxyribose. E) transformation causes protein to be brought into the cell.

C

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

C

26) An Okazaki fragment has which of the following arrangements? A) primase, polymerase, ligase B) 3' RNA nucleotides, DNA nucleotides 5' C) 5' RNA nucleotides, DNA nucleotides 3' D) DNA polymerase I, DNA polymerase III48 E) 5' DNA to

C

28) Which enzyme catalyzes the elongation of a DNA strand in the 5' _ 3' direction? A) primase B) DNA ligase C) DNA polymerase III D) topoisomerase E) helicase

C

29) What determines the nucleotide sequence of the newly synthesized strand during DNA replication? A) the particular DNA polymerase catalyzing the reaction B) the relative amounts of the four nucleoside triphosphates in the cell C) the nucleotide sequence of the template strand D) the primase used in the reaction E) the arrangement of histones in the sugar phosphate backbone

C

30) Eukaryotic telomeres replicate differently than the rest of the chromosome. This is a consequence of which of the following? A) The evolution 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 because of the need for a 3' onto which nucleotides can attach D) Gaps left at the 3' end of the lagging strand because of the need for a primer E) The "no ends" of a circular chromosome

C

37) 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 end of a growing DNA strand D) to degrade damaged DNA molecules E) to rejoin the two DNA strands (one new and one old) after replication

C

In which progeny phenotypes has there been recombination between genes A and B?

1, 2, 5, and 6

4 Common Cellular Features

1. Plasma membrane 2. DNA Region 3. Cytoplasm 4. Free Ribosomes

Cell Theory

1. The cell is the basic unit of life. 2. All cells arise from pre-existing cells. 3. All organisms are composed of one or more cells.

Classification of organisms on the cellular level

1. Unicellular: bacteria, some protists such as amoeba, paramecia, etc. 2. Multicellular: humans, trees, etc. 3. Prokaryiotic: bacteria, and blue-green algae only; no nucleus 4. Eukaryotic: animals, plants (multicellular), some protists (unicellular); have a nucleus

A certain kind of snail can have a right-handed direction of shell coiling (D) or left-handed coiling (d). 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)?

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

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 x BBtt will be expected to have black fur and long tails?

1/2.

If nondisjunction occurs in meiosis II during gametogenesis, what will be the result at the completion of meiosis?

1/4 of the gametes will be n + 1, 1/4 will be n - 1, and 1/2 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 that has been exchanged with a portion of his chromosome 12. Although he is normal because 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?

1/4 will be normal, 1/4 will have the translocation, and 1/2 will have duplications and deletions

In the cross AaBbCc x AaBbCc, what is the probability of producing the genotype AABBCC?

1/64.

Cinnabar eyes 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?

100%

They have a daughter who is a dwarf with normal color vision. What is the probability that she is heterozygous for both genes?

100%

A diploid cell (2n) has how many sets of chromosomes

2

Each replicated chromosome consists of ____ identical sister chromatids

2

sexual reproduction

2 parents give rise to offspring that have uniquecombinations of genes inherited from the 2 parents

There are ____ chromosomes in a human somatic cell

2 sets of 23; one from the mother and one from the father 46 total

Bacteria

20x larger than viruses; made up of DNA; unicellular; asexual reproduction, independent of host

Each set of 23 consists of

22 autosomes and a single sex chromosome

For humans the diploid number is

23 (2n=46)

For humans the haploid number is

23 (n=23) only occurs in gametes or non somatic cells

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?

2:1 male to female

The number of combinations possible when chromosomes assort independently into gametes is ____

2n (n=haploid number)

If recombination is equal to distance in centimorgans (cM), what is the approximate distance between genes A and B?

3 cM

Glycerol

3 carbon alcohol with a hydroxyl group attached to each carbon.

Photorespiration lowers the efficiency of photosynthesis by preventing the formation of

3-phosphoglycerate molecules

Given the parents AABBCc x AabbCc, assume simple dominance for each trait and independent assortment. What proportion of the progeny will be expected to phenotypically resemble the first parent?

3/4.

Which of the following are the phenotypes of the parents in this cross?

4 and 8

The result after Meiosis l & ll

4 haploid daughter cells with unreplicated chromosomes

Which of the following is true of aneuploidies in general?

45 X is the only known human live-born monosomy

Of the following human aneuploidies, which is the one that generally has the most severe impact on the health of the individual?

47, +21

When crossing an organism that is homozygous recessive for a single trait with a heterozygote, what is the chance of producing an offspring with the homozygous recessive phenotype?

50%.

In humans, male-pattern baldness is controlled by an autosomal gene that occurs in two allelic forms. Allele Hn determines nonbaldness, and allele Hb determines pattern baldness. In males, because of the presence of testosterone, allele Hb is dominant over Hn. If a man and woman both with genotype HnHb have a son, what is the chance that he will eventually be bald?

75%

How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEE?

8.

102) Professor Jamey Marth at the University of California, Santa Barbara, identified 70 molecules that are used to build cellular macromolecules and structures. These include at least 34 saccharides, 8 nucleosides, and 20 amino acids. In theory, then, which class of biological polymer has the greatest information-coding capacity? A) polysaccharides B) proteins C) DNA D) RNA

A

3) Which of the following is a statement of the first law of thermodynamics?

A) Energy cannot be created or destroyed.

A chemical reaction that has a negative delta G is correctly described as

A) Exergonic

Which of the following is not true of RNA processing?

A) Exons are cut out before mRNA leaves the nucleus.

What is the function of GTP in translation?

A) GTP energizes the formation of the initiation complex, using initiation factors.

64) Which statement best supports the hypothesis that glycolysis is an ancient metabolic pathway that originated before the last universal common ancestor of life on Earth?

A) Glycolysis is widespread and is found in the domains Bacteria, Archaea, and Eukarya.

19) The first cell whose entire genome was sequenced was which of the following? A) H. influenzae in 1995 B) H. sapiens in 2001 C) rice in 1955 D) tobacco mosaic virus E) HIV in 1998

A) H. influenzae in 1995

29) A young animal has never had much energy. He is brought to a veterinarian for help and is sent to the animal hospital for some tests. There they discover his 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 his condition?

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

The "universal" genetic code is now known to have exceptions. Evidence for this can be found if which of the following is true?

A) If UGA, usually a stop codon, is found to code for an amino acid such as tryptophan (usually coded for by UGG only).

Succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by malonic acid, which resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the ratio of succinate to malonic acid reduces the inhibitory effect of malonic acid. 72) What is malonic acid's role with respect to succinate dehydrogenase?

A) It is a competitive inhibitor.

Which of the following is characteristic of the product of the p53 gene?

A) It is an activator for other genes.

70) You have a friend who lost 7 kg (about 15 pounds) of fat on a regimen of strict diet and exercise. How did the fat leave her body?

A) It was released as CO2 and H2O.

55) Scientists developed a set of guidelines to address the safety of DNA technology. Which of the following is one of the adopted safety measures? A) Microorganisms used in recombinant DNA experiments are genetically crippled to ensure that they cannot survive outside of the laboratory. B) Genetically modified organisms are not allowed to be part of our food supply. C) Transgenic plants are engineered so that the plant genes cannot hybridize. D) Experiments involving HIV or other potentially dangerous viruses have been banned. E) Recombinant plasmids cannot be replicated.

A) Microorganisms used in recombinant DNA experiments are genetically crippled to ensure that they cannot survive outside of the laboratory.

8) Which of the following statements describes NAD+?

A) NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid cycle.

The phenomenon in which RNA molecules in a cell are destroyed if they have a sequence complementary to an introduced double-stranded RNA is called

A) RNA interference.

37) Which was developed by a British researcher and causes DNA sequences to be transferred to a membrane and identified with a probe? A) Southern blotting B) Northern blotting C) Western blotting D) Eastern blotting E) RT-PCR

A) Southern blotting

Which of the following can influence enzyme activity?

A) Temperature B) pH C) substrate concentration D) competitive inhibitor ALL

48) A researcher is using adult stem cells and comparing them to other adult cells from the same tissue. Which of the following is a likely finding? A) The cells from the two sources exhibit different patterns of DNA methylation. B) Adult stem cells have more DNA nucleotides than their counterparts. C) The two kinds of cells have virtually identical gene expression patterns in microarrays. D) The non-stem cells have fewer repressed genes. E) The non-stem cells have lost the promoters for more genes.

A) The cells from the two sources exhibit different patterns of DNA methylation.

3) When electrons move closer to a more electronegative atom, what happens?

A) The more electronegative atom is reduced, and energy is released.

69) A mutation in yeast makes it unable to convert pyruvate to ethanol. How will this mutation affect these yeast cells?

A) The mutant yeast will be unable to grow anaerobically.

106) When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs?

A) The pH of the matrix increases.

31) Which of the following statements is true about enzyme-catalyzed reactions?

A) The reaction is faster than the same reaction in the absence of the enzyme.

What do gap genes, pair-rule genes, segment polarity genes, and homeotic genes all have in common?

A) Their products act as transcription factors.

22) Which of the following statements is true for the class of biological molecules known as lipids? A) They are insoluble in water. B) They are made from glycerol, fatty acids, and phosphate. C) They contain less energy than proteins and carbohydrates. D) They are made by dehydration reactions. E) They contain nitrogen.

A) They are insoluble in water.

Which of the following statements describes proto-oncogenes?

A) They can code for proteins associated with cell growth.

Which of the following DNA mutations is the most likely to be damaging to the protein it specifies?

A) a base-pair deletion

Which of the following is most likely to have a small protein called ubiquitin attached to it?

A) a cyclin that usually acts in G1, now that the cell is in G2

Which of the following best describes siRNA?

A) a short double-stranded RNA, one of whose strands can complement and inactivate a sequence of mRNA

41) Which of the following covalently connects segments of DNA? A) helicase B) DNA polymerase III C) ligase D) DNA polymerase I E) primase

C

42) The tertiary structure of a protein is the A) bonding together of several polypeptide chains by weak bonds. B) order in which amino acids are joined in a polypeptide chain. C) unique three-dimensional shape of the fully folded polypeptide. D) organization of a polypeptide chain into an α helix or β pleated sheet. E) overall protein structure resulting from the aggregation of two or more polypeptide subunits.

C

44) At which level of protein structure are interactions between the side chains (R groups) most important? A) primary B) secondary C) tertiary D) quaternary E) all of the above

C

48) What is the role of DNA ligase in the elongation of the lagging strand during DNA replication? A) synthesize RNA nucleotides to make a primer B) catalyze the lengthening of telomeres C) join Okazaki fragments together D) unwind the parental double helix E) stabilize the unwound parental DNA

C

52) If cells are grown in a medium containing radioactive 35S, which of these molecules will be labeled? A) phospholipids B) nucleic acids C) proteins D) amylose E) both proteins and nucleic acids

C

56) About how many more genes are there in the haploid human genome than in a typical bacterial genome? A) 10 X B) 100 X C) 1000 X D) 10,000 X54 E) 100,000 X

C

57) If 14C-labeled uridine triphosphate is added to the growth medium of cells, what macromolecules will be labeled? A) phospholipids B) DNA C) RNA D) both DNA and RNA E) proteins

C

58) 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 pentose sugar C) a nitrogenous base, a phosphate group, and a pentose sugar D) a phosphate group and an adenine or uracil E) a pentose sugar and a purine or pyrimidine

C

61) If a DNA sample were composed of 10% thymine, what would be the percentage of guanine? A) 10 B) 20 C) 40 D) 80 E) impossible to tell from the information given

C

64) Which of the following statements best summarizes the differences between DNA and RNA? A) DNA encodes hereditary information, whereas RNA does not. B) The bases in DNA form base-paired duplexes, whereas the bases in RNA do not. C) DNA nucleotides contain a different sugar than RNA nucleotides. D) DNA contains the base uracil, whereas RNA contains the base thymine. E) DNA encodes hereditary information, whereas RNA does not; the bases in DNA form base-paired duplexes, whereas the bases in RNA do not; and DNA nucleotides contain a different sugar than RNA nucleotides.

C

64) Which of the following statements is true 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. E) Only euchromatin is visible under the light microscope.

C

72) Which of the following is not a monomer/polymer pairing? A) monosaccharide/polysaccharide B) amino acid/protein C) triglyceride/phospholipid bilayer D) deoxyribonucleotide/DNA E) ribonucleotide/RNA

C

76) Which of the following statements is true regarding the molecule illustrated in Figure 5.3? A) It is a saturated fatty acid. B) A diet rich in this molecule may contribute to atherosclerosis. C) Molecules of this type are usually liquid at room temperature. D) It is a saturated fatty acid and a diet rich in this molecule may contribute to atherosclerosis. E) It is a saturated fatty acid, a diet rich in this molecule may contribute to atherosclerosis, and molecules of this type are usually liquid at room temperature.

C

78) What is the structure shown in Figure 5.4? A) pentose molecule B) fatty acid molecule C) steroid molecule D) oligosaccharide molecule E) phospholipid molecule

C

8) Which of the following investigators was/were responsible for the following discovery? Chemicals from heat-killed S cells were purified. The chemicals were tested for the ability to transform live R cells. The transforming agent was found to be DNA. A) Frederick Griffith B) Alfred Hershey and Martha Chase C) Oswald Avery, Maclyn McCarty, and Colin MacLeod D) Erwin Chargaff E) Matthew Meselson and Franklin Stahl

C

80) At which bond would water need to be added to achieve hydrolysis of the peptide, back to its component amino acid? A) A B) B C) C D) D E) E

C

81) Which bond is a peptide bond? A) A B) B C) C D) D E) E

C

87) Which molecule is glycerol? A) 1 B) 6 C) 10 D) 14 E) 15

C

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

C

Approximately 32 different monomeric carbohydrate subunits are found in various natural polysaccharides. Proteins are composed of 20 different amino acids. DNA and RNA are each synthesized from four nucleotides. 100) Among these biological polymers, which has the least structural variety? A) polysaccharides B) proteins C) DNA D) RNA

C

18) Which of the following shows the correct changes in thermodynamic properties for a chemical reaction in which amino acids are linked to form a protein?

C) +ΔH, -ΔS, +ΔG

49) If a cell is able to synthesize 30 ATP molecules for each molecule of glucose completely oxidized by carbon dioxide and water, how many ATP molecules can the cell synthesize for each molecule of pyruvate oxidized to carbon dioxide and water?

C) 12

95) What happens at the end of the chain in Figure 9.3?

C) 4 electrons combine with a molecule of oxygen and 4 protons.

44) How many oxygen molecules (O2) are required each time a molecule of glucose (C6H12O6) is completely oxidized to carbon dioxide and water via aerobic respiration,?

C) 6

If a protein is coded for by a single gene and this protein has six clearly defined domains, which number of exons below is the gene likely to have?

C) 8

34) Upon chemical analysis, a particular polypeptide was found to contain 100 amino acids. How many peptide bonds are present in this protein? A) 101 B) 100 C) 99 D) 98 E) 97

C) 99

89) If pyruvate oxidation is blocked, what will happen to the levels of oxaloacetate and citric acid in the citric acid cycle shown in Figure 9.2?

C) Oxaloacetate will accumulate and citric acid will decrease.

During splicing, which molecular component of the spliceosome catalyzes the excision reaction?

C) RNA

In eukaryotes there are several different types of RNA polymerase. Which type is involved in transcription of mRNA for a globin protein?

C) RNA polymerase II

For a repressible operon to be transcribed, which of the following must occur?

C) RNA polymerase must bind to the promoter, and the repressor must be inactive.

Succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by malonic acid, which resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the ratio of succinate to malonic acid reduces the inhibitory effect of malonic acid. 71) Based on this information, which of the following is correct?

C) Succinate is the substrate, and fumarate is the product.

An experimenter has altered the 3' end of the tRNA corresponding to the amino acid methionine in such a way as to remove the 3' AC. Which of the following hypotheses describes the most likely result?

C) The amino acid methionine will not bind.

In a system where temperature is uniform, free energy is

C) The energy available to do work

56) One successful form of gene therapy has involved delivery of an allele for the enzyme adenosine deaminase (ADA) to bone marrow cells of a child with SCID, and delivery of these engineered cells back to the bone marrow of the affected child. What is one major reason for the success of this procedure as opposed to many other efforts at gene therapy? A) The engineered bone marrow cells from this patient can be used for any other SCID patient. B) The ADA introduced allele causes all other ADA-negative cells to die. C) The engineered cells, when reintroduced into the patient, find their way back to the bone marrow. D) No vector is required to introduce the allele into ADA-negative cells E) The immune system fails to recognize cells with the variant gene

C) The engineered cells, when reintroduced into the patient, find their way back to the bone marrow.

Which of the following is true for exergonic reactions?

C) The products have more free energy than the reactants

One of the human leukemias, called CML (chronic myelogenous leukemia) is associated with a chromosomal translocation between chromosomes 9 and 22 in somatic cells of bone marrow. Which of the following allows CML to provide further evidence of this multi-step nature of cancer?

C) The translocation requires breaks in both chromosomes 9 and 22, followed by fusion between the reciprocal pieces.

24) Which of the following is true regarding saturated fatty acids? A) They are the predominant fatty acid in corn oil. B) They have double bonds between carbon atoms of the fatty acids. C) They are the principal molecules in lard and butter. D) They are usually liquid at room temperature. E) They are usually produced by plants.

C) They are the principal molecules in lard and butter.

2) Which of the following is (are) true for anabolic pathways?

C) They consume energy to build up polymers from monomers.

How do cells overcome the energy barriers that would otherwise inhibit spontaneous reactions from proceeding?

C) They have enzymes that lower the activation energy

38) Which describes the transfer of polypeptide sequences to a membrane to analyze gene expression? A) Southern blotting B) Northern blotting C) Western blotting D) Eastern blotting E) RT-PCR

C) Western blotting

If she moves the operator to the far end of the operon (past the transacetylase gene), which of the following would likely occur when the cell is exposed to lactose?

D) The structural genes will be transcribed continuously.

76) Most cells cannot harness heat to perform work because

C) temperature is usually uniform throughout a cell.

33) A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because

C) the activation energy barrier for this reaction cannot be surmounted.

61) As genetic technology makes testing for a wide variety of genotypes possible, which of the following is likely to be an increasingly troublesome issue? A) use of genotype information to provide positive identification of criminals B) using technology to identify genes that cause criminal behaviors C) the need to legislate for the protection of the privacy of genetic information D) discrimination against certain racial groups because of major genetic differences E) alteration of human phenotypes to prevent early disease mRNAs

C) the need to legislate for the protection of the privacy of genetic information

Which of the following is an example of post-transcriptional control of gene expression?

C) the removal of introns and splicing together of exons

The researcher in question measures the amount of new polypeptide production in embryos from 2—8 hours following fertilization and the results show a steady and significant rise in polypeptide concentration over that time. The researcher concludes that

C) the resulting new polypeptides are due to translation of maternal mRNAs.

In the structural organization of many eukaryotic genes, individual exons may be related to which of the following?

C) the various domains of the polypeptide product

79) Some bacteria are metabolically active in hot springs because

C) their enzymes have high optimal temperatures.

97) Why is coenzyme A, a sulfur-containing molecule derived from a B vitamin, added?

C) to provide a relatively unstable molecule whose acetyl portion can be readily transferred to a compound in the citric acid cycle

A cell that remains entirely flexible in its developmental possibilities is said to be

C) totipotent.

In most cases, differentiation is controlled at which level?

C) transcription

53) An important group of peripheral membrane proteins are enzymes such as the phospholipases that cleave the head groups of phospholipids. What properties must these enzymes exhibit?

C) water solubility

14) The mathematical expression for the change in free energy of a system is ΔG =ΔH - TΔS. Which of the following is (are) correct?

C) ΔG is the change in free energy.

8) How many molecules of water are needed to completely hydrolyze a polymer that is 11 monomers long? A) 12 B) 11 C) 10 D) 9 E) 8

C. 10

4 classes of large biological molecules

Carbohydrates, lipids, proteins, and nucleic acids

Emergent Properties of Multicellular Organisms

Cell ---> Tissue ---> Organ ---> Organ System ---> Mollecular Organism

Eukaryote

Cells containing membrane-enclosed organelles

Prokaryote

Cells lacking a nucleus or other membrane-enclosed organelles.

Each tetrad usually has one or more _______

Chiasmata (X-shaped regions where crossing over occurred)

Telophase ll

Chromosomes arrive at opposite poles Nuclei form, chromosomes begin decondensing

Prophase l

Chromosomes condense crossing over occurs

In 1956 Tijo and Levan first successfully counted human chromosomes. What is the reason it took so many years to do so?

Chromosomes were piled up on top of one another in the nucleus, chromosomes were not distinguishable during interphase, and a method had not yet been devised to halt mitosis at metaphase

Biosphere

Consists of all life on Earth and all parts of the Earth in which life exists, including land, water, and the atmosphere.

"Secondary" structure of protein

Consists of coils and folds in the polypeptide chain. Found in fibrous materials. Hydrogen bonds make these very strong. Spider Web.

Functional protein

Consists of one or more polypeptides precisely twisted, folded, and coiled into a unique shape. This structure determines its function.

"Primary" structure of protein

Consists of the basic sequence of amino acids in the polypeptide chain. The primary structure is held together by peptide bonds.

Fats

Constructed from glycerol and fatty acids

How could you best predict the max number of alleles for a single gene whose polypeptide product is known?

Count the number of DNA nucleotides that are in the code for polypeptides.

Recombination between linked genes comes about for what reason?

Crossovers between these genes result in chromosomal exchange

10) Which of the following investigators was/were responsible for the following discovery? 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) Frederick Griffith B) Alfred Hershey and Martha Chase C) Oswald Avery, Maclyn McCarty, and Colin MacLeod D) Erwin Chargaff E) Matthew Meselson and Franklin Stahl

D

103) Which of the following categories includes all others in the list? A) monosaccharide B) disaccharide C) starch D) carbohydrate E) polysaccharide

D

109) Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA? A) 5'-purine-pyrimidine-purine-pyrimidine-3' with 3'-purine-pyrimidine-purine-pyrimidine-5' B) 5'-AGCT-3' with 5'-TCGA-3' C) 5'-GCGC-3' with 5'-TATA-3' D) 5'-ATGC-3' with 5'-GCAT-3' E) All of these pairs are correct.

D

Which of the following would be his most logical assumption?

D) The substance is produced in region 1 and diffuses toward region 5.

37) According to the induced fit hypothesis of enzyme catalysis, which of the following is correct?

D) The binding of the substrate changes the shape of the enzyme's active site.

25) Large organic molecules are usually assembled by polymerization of a few kinds of simple subunits. Which of the following is an exception to this statement? A) a steroid B) cellulose C) DNA D) an enzyme E) a contractile protein

A) a steroid

When the genome of a particular species is said to include 20,000 protein-coding regions, what does this imply?

D) There are also genes for RNAs other than mRNA.

14) Why are carbohydrates and fats considered high energy foods?

D) They have a lot of electrons associated with hydrogen.

24) The transport of pyruvate into mitochondria depends on the proton-motive force across the inner mitochondrial membrane. How does pyruvate enter the mitochondrion?

A) active transport

78) 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.

Enzymes act as catalysts by

A) lowering the activation energy of an exergonic reaction

A transcription unit that is 8,000 nucleotides long may use 1,200 nucleotides to make a protein consisting of approximately 400 amino acids. This is best explained by the fact that

A) many noncoding stretches of nucleotides are present in mRNA.

Garrod hypothesized that "inborn errors of metabolism" such as alkaptonuria occur because

A) metabolic enzymes require vitamin cofactors, and affected individuals have significant nutritional deficiencies.

plasmodesmata

(2) openings in plant cell walls through which strands of ER and cytosol connect adjacent cells

stroma

(A) innermost compartment of chloroplast (Calvin cycle SITE)

tight junctions

(A) membrane fusions of neighboring cells that prevent leakage of fluid between them

cilia

(A) short, many extensions of membrane-covered microtubules that move cell or materials past cell (ex. paramecium, trachea)

middle lamina

(A) thin layer of adhesive extracellular material (pectins) between primary walls of adjacent young plant cells

desmosomes

(B) anchoring junctions that prevents cells subjected to mechanical stress from being pulled apart

grana

(B) stacked thylakoid membranes in chloroplast

primary cell wall

(B) thin, flexible and furthest out because it is secreted first

gap junctions

(C) cytoplasmic channels between adjacent animal cells that allow movement of materials

thylakoids

(C) flattened membrane sacs in chloroplast (Light Reactions SITE)

secondary cell wall

(C) strong, durable matrix added between plasma membrane and outermost structure for structure and support

mitochondrial matrix

(D) internal compartment of mitochondria (Krebs cycle SITE)

cristae

(E) inner membrane infoldinfgs of mitochondria that increase surface area (Electron Transport Chain and ATP synthase SITE)

flagella

(E) long, few, whiplike tails of membrane-covered microtubules that move cells

microtubules

(bottom) thickest, hollow tubes of tubulin proteins that make up cilia, flagella, and mitotic spindle and help move organelles around cell

intermediate filaments

(middle) medium, coiled fibers of keratin that help maintain cell shape, stabilize positions of organelles

microfilaments

(top) thinnest, intertwined fibers of actin proteins that allow cytoplasmic streaming, ameboid movement and keep cell extensions rigid (microvilli, axons)

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 might then occur to make the cancer worse?

) expression of inappropriate gene products

Women (and all female mammals) have one active X chromosome per cell instead of two. What causes this?

) modification of the XIST gene so that it is active only on one X chromosome, which then becomes inactive

In certain plants, tall is dominant to short. If a heterozygous plant is crossed with a homozygous tall plant, what is the probability that the offspring will be short?

0.

The centimorgan (cM) is a unit named in honor of Thomas Hunt Morgan. To what is it equal?

1% frequency of recombination between two genes

104) The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are in the α form. Which of the following could amylase break down? A) glycogen, starch, and amylopectin B) glycogen and cellulose C) cellulose and chitin D) starch and chitin E) starch, amylopectin, and cellulose

A

106) The structural level of a protein least affected by a disruption in hydrogen bonding is the A) primary level. B) secondary level. C) tertiary level. D) quaternary level. E) All structural levels are equally affected.

A

12) Cytosine makes up 38% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this sample will be thymine? A) 12 B) 24 C) 31 D) 38 E) It cannot be determined from the information provided.

A

14) Which of the following can be determined directly from X-ray diffraction photographs of crystallized DNA? A) the diameter of the helix B) the rate of replication C) the sequence of nucleotides D) the bond angles of the subunits E) the frequency of A vs. T nucleotides

A

15) Why does the DNA double helix have a uniform diameter? A) Purines pair with pyrimidines. B) C nucleotides pair with A nucleotides. C) Deoxyribose sugars bind with ribose sugars. D) Nucleotides bind with nucleosides. E) Nucleotides bind with nucleoside triphosphates

A

16) What kind of chemical bond is found between paired bases of the DNA double helix? A) hydrogen B) ionic46 C) covalent D) sulfhydryl E) phosphate

A

17) It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information in which of the following? A) sequence of bases B) phosphate-sugar backbones C) complementary pairing of bases D) side groups of nitrogenous bases E) different five-carbon sugars

A

19) Mendel and Morgan did not know about the structure of DNA; however, which of the following of their contributions was (were) necessary to Watson and Crick? A) the particulate nature of the hereditary material B) dominance vs. recessiveness C) sex-linkage D) genetic distance and mapping E) the usefulness of peas and Drosophila

A

33) In an experiment, DNA is allowed to replicate in an environment with all necessary enzymes, dATP, dCTP, dGTP, and radioactively labeled dTTP ( 3H thymidine) for several minutes and then switched to nonradioactive medium. It is then viewed by electron microscopy and autoradiography. The drawing below represents the results. Grains represent radioactive material within the replicating eye.(Refer to figure 16.2 in test bank) Which is the most likely interpretation? A) There are two replication forks going in opposite directions. B) Thymidine is only being added where the DNA strands are furthest apart. C) Thymidine is only added at the very beginning of replication. D) Replication proceeds in one direction only.

A

37) Which bonds are created during the formation of the primary structure of a protein? A) peptide bonds B) hydrogen bonds C) disulfide bonds D) phosphodiester bonds E) peptide bonds, hydrogen bonds, and disulfide bonds

A

38) 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). These two classes of DNA probably 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. E) RNA primers and mitochondrial DNA.

A

40) Which of the following separates the DNA strands during replication? A) helicase B) DNA polymerase III C) ligase D) DNA polymerase I E) primase

A

43) The difference between ATP and the nucleoside triphosphates used during DNA synthesis is that A) the nucleoside triphosphates have the sugar deoxyribose; ATP has the sugar ribose. B) the nucleoside triphosphates have two phosphate groups; ATP has three phosphate groups. C) ATP contains three high-energy bonds; the nucleoside triphosphates have two. D) ATP is found only in human cells; the nucleoside triphosphates are found in all animal and plant cells. E) triphosphate monomers are active in the nucleoside triphosphates, but not in ATP

A

44) The leading and the lagging strands differ in that 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.

A

47) What is the function of topoisomerase? A) relieving strain in the DNA ahead of the replication fork B) elongation of new DNA at a replication fork by addition of nucleotides to the existing chain C) the addition of methyl groups to bases of DNA D) unwinding of the double helix E) stabilizing single-stranded DNA at the replication fork

A

52) Which of the following sets of materials are required by both eukaryotes and prokaryotes for replication? A) double-stranded DNA, 4 kinds of dNTPs, primers, origins B) topoisomerases, telomerase, polymerases C) G-C rich regions, polymerases, chromosome nicks D) nucleosome loosening, 4 dNTPs, 4 rNTPs E) ligase, primers, nucleases

A

62) Why do histones 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. E) Histones are highly hydrophobic, and DNA is hydrophilic.

A

63) Which of the following 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) looped domain, nucleosome, 30-nm chromatin fiber D) nucleosome, looped domain, 30-nm chromatin fiber E) 30-nm chromatin fiber, nucleosome, looped domain

A

The gene for which protein would most likely be expressed as a result of MyoD activity?

A) myosin

73) If two molecules of the general type shown in Figure 5.1 were linked together, carbon-1 of one molecule to carbon-4 of the other, the single molecule that would result would be A) maltose. B) fructose. C) glucose. D) galactose. E) sucrose.

A

82) Which bond is closest to the amino terminus of the molecule? A) A B) B C) C D) D E) E

A

97) Which of the following molecules has a functional group that frequently forms covalent bonds that maintain the tertiary structure of a protein? A) 2 B) 3 C) 7 D) 8 E) 9

A

Genome

A "library" of genetic instructions that an organism inherits.

Between which two genes would you expect the highest frequency of recombination?

A and G

What do we mean when we use the terms monohybrid cross and dihybrid cross?

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

Constant

A factor in an experiment that does not change.

How long can viruses survive outside the host?

A few seconds to minutes.

Organelle

A functional component present in a cell. Organelle is to cell as organ is to organ system. Example: mitochondria

Clone

A group of genetically identical individuals from the same parent formed by asexual reproduction

Negative Feedback Mechanism

A loop in which the response reduces the initial stimulus.

Positive Feedback Mechanism

A loop in which the response speeds up its own production.

Feedback Regulation

A process in which the output, or product, of a process regulates the very process itself.

Asexual reproduction

A single individual passes genes to its offspring without the fusion of gametes

A gamete contains how many sets of chromosomes and what is it called

A single set Haploid (n)

Glycogen

A storage polysaccharide in animals. (within liver & muscle cells)

Starch

A storage polysaccharide of plants - consists entirely of glucose monomers. (within chloroplasts & plastids)

D) disulfide bond. HINT: Think, three-dimensional - tertiary protein structure

A strong covalent bond between amino acids that functions in maintaining a polypeptide's specific three-dimensional shape is a (an) A) ionic bond. B) hydrophobic interaction. C) van der Waals interaction. D) disulfide bond. E) hydrogen bond.

Inductive Reasoning

A type of logic in which generalizations are based on a large number of specific observations. Seeks to reduce uncertainty of claims. "Informal" - looks for probability, not certainty.

Deductive Reasoning

A type of logic in which specific results are predicted from a general premise. Seeks absolute certainty of conclusions. "Formal" - seeks truth and certainty, not probability.

Gene

A unit of inheritance made of DNA, a nucleic acid made of monomers called nucleotides.

86) Starting with one molecule of isocitrate and ending with fumarate, how many ATP molecules can be made through substrate-level phosphorylation (see Figure 9.2)?

A) 1

16) Which of the following best describes the complete sequence of steps occurring during every cycle of PCR? 1. The primers hybridize to the target DNA. 2. The mixture is heated to a high temperature to denature the double stranded target DNA. 3. Fresh DNA polymerase is added. 4. DNA polymerase extends the primers to make a copy of the target DNA. A) 2, 1, 4 B) 1, 3, 2, 4 C) 3, 4, 1, 2 D) 3, 4, 2 E) 2, 3, 4

A) 2, 1, 4

A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is

A) 3' UCA 5'.

84) Which portion of the pathway in Figure 9.1 involves an endergonic reaction?

A) A

85) Which portion of the pathway in Figure 9.1 contains a phosphorylation reaction in which ATP is the phosphate source?

A) A

The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following?

A) A gene from an organism can theoretically be expressed by any other organism.

A geneticist introduces a transgene into yeast cells and isolates five independent cell lines in which the transgene has integrated into the yeast genome. In four of the lines, the transgene is expressed strongly, but in the fifth there is no expression at all. Which is a likely explanation for the lack of transgene expression in the fifth cell line?

A) A transgene integrated into a heterochromatic region of the genome.

60) In the absence of oxygen, yeast cells can obtain energy by fermentation, resulting in the production of

A) ATP, CO2, and ethanol (ethyl alcohol).

5) Which of the following statements describes the results of this reaction? C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy

A) C6H12O6 is oxidized and O2 is reduced.

9) Which of the following best summarizes the relationship between dehydration reactions and hydrolysis? A) Dehydration reactions assemble polymers, and hydrolysis reactions break down polymers. B) Dehydration reactions eliminate water from lipid membranes, and hydrolysis makes lipid membranes water permeable. C) Dehydration reactions can occur only after hydrolysis. D) Hydrolysis creates monomers, and dehydration reactions break down polymers. E) Dehydration reactions ionize water molecules and add hydroxyl groups to polymers; hydrolysis reactions release hydroxyl groups from polymers.

A) Dehydration reactions assemble polymers, and hydrolysis reactions break down polymers.

Gene expression in the domain Archaea in part resembles that of bacteria and in part that of the domain Eukarya. In which way is it most like the domain Eukarya?

A) Domain Archaea have numerous transcription factors.

4) How does a bacterial cell protect its own DNA from restriction enzymes? A) adding methyl groups to adenines and cytosines B) using DNA ligase to seal the bacterial DNA into a closed circle C) adding histones to protect the double-stranded DNA D) forming "sticky ends" of bacterial DNA to prevent the enzyme from attaching E) reinforcing the bacterial DNA structure with covalent phosphodiester bonds

A) adding methyl groups to adenines and cytosines

98) After the first disruption, when electron transfer and ATP synthesis still occur, what must be present?

A) all of the electron transport proteins as well as ATP synthase

30) Which of the following modifications is least likely to alter the rate at which a DNA fragment moves through a gel during electrophoresis? A) altering the nucleotide sequence of the DNA fragment B) methylating the cytosine bases within the DNA fragment C) increasing the length of the DNA fragment D) decreasing the length of the DNA fragment E) neutralizing the negative charges within the DNA fragment

A) altering the nucleotide sequence of the DNA fragment

When the ribosome reaches a stop codon on the mRNA, no corresponding tRNA enters the A site. If the translation reaction were to be experimentally stopped at this point, which of the following would you be able to isolate?

A) an assembled ribosome with a polypeptide attached to the tRNA in the P site

If there are two children born from the same parents, and child one inherits a predisposition to retinoblastoma (one of the mutations) and child two does not, but both children develop the retinoblastoma, which of the following would you expect?

A) an earlier age of onset in child one

9) Which of the following types of reactions would decrease the entropy within a cell?

A) anabolic reactions

13) On food packages, to what does the term insoluble fiber refer? A) cellulose B) polypeptides C) starch D) amylopectin E) chitin

A) cellulose

A genetic test to detect predisposition to cancer would likely examine the APC gene for involvement in which type(s) of cancer?

A) colorectal only

The anticodon of a particular tRNA molecule is

A) complementary to the corresponding mRNA codon.

A mutation that inactivates the regulatory gene of a repressible operon in an E. coli cell would result in

A) continuous transcription of the structural gene controlled by that regulator.

Which of the following serve as sources of developmental information?

A) cytoplasmic determinants such as mRNAs and proteins produced before fertilization

The general process that leads to the differentiation of cells is called

A) determination.

The process of cellular differentiation is a direct result of

A) differential gene expression.

The fact that plants can be cloned from somatic cells demonstrates that

A) differentiated cells retain all the genes of the zygote.

In animals, embryonic stem cells differ from adult stem cells in that

A) embryonic stem cells are totipotent, and adult stem cells are pluripotent.

20) A chemical reaction that has a positive ΔG is correctly described as

A) endergonic.

Muscle cells differ from nerve cells mainly because they

A) express different genes.

3) Which of these molecules is not formed by dehydration reactions? A) fatty acids B) disaccharides C) DNA D) protein E) amylose

A) fatty acids

77) What carbon sources can yeast cells metabolize to make ATP from ADP under anaerobic conditions?

A) glucose

80) 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

12) The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are the α form. Which of the following could amylase break down? A) glycogen B) cellulose C) chitin D) glycogen and chitin only E) glycogen, cellulose, and chitin

A) glycogen

56) Which of the following normally occurs regardless of whether or not oxygen (O2) is present?

A) glycolysis

57) Which of the following occurs in the cytosol of a eukaryotic cell?

A) glycolysis and fermentation

10) Biological evolution of life on Earth, from simple prokaryote-like cells to large, multicellar eukaryotic organisms,

A) has occurred in accordance with the laws of thermodynamics.

Eukaryotic cells can control gene expression by which of the following mechanisms?

A) histone acetylation of nucleosomes

Mutations in these genes lead to transformations in the identity of entire body parts:

A) homeotic genes

43) Some of the drugs used to treat HIV patients are competitive inhibitors of the HIV reverse transcriptase enzyme. Unfortunately, the high mutation rate of HIV means that the virus rapidly acquires mutations with amino acid changes that make them resistant to these competitive inhibitors. Where in the reverse transcriptase enzyme would such amino acid changes most likely occur in drug-resistant viruses?

A) in or near the active site

Diffusion occurs as the result of the

A) increase in entropy

A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. In one set of experiments she succeeded in decreasing methylation of histone tails. Which of the following results would she most likely see?

A) increased chromatin condensation

72) Phosphofructokinase is an allosteric enzyme that catalyzes the conversion of fructose 6-phosphate to fructose 1,6-bisphosphate, an early step of glycolysis. In the presence of oxygen, an increase in the amount of ATP in a cell would be expected to

A) inhibit the enzyme and thus slow the rates of glycolysis and the citric acid cycle.

20) Replication in prokaryotes differs from replication in eukaryotes for which of these reasons? A) The prokaryotic chromosome has 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. E) Prokaryotes have telomeres, and eukaryotes do not.

B

21) What is meant by the description "antiparallel" regarding the strands that make up DNA? A) The twisting nature 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 is positively charged and the other is negatively charged. E) One strand contains only purines and the other contains only pyrimidines.

B

24) 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 Figure 16.1 would you expect if the DNA was replicated in a conservative manner? A) Only 15N DNA B) 15N DNA & 14N DNA C) Only 14N DNA D) 14N-15N hybrid DNA E) 14N-15N hybrid DNA & 14N DNA

B

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

B

33) The segment of DNA shown in Figure 20.2 has restriction sites I and II, which create restriction fragments A, B, and C. Which of the gels produced by electrophoresis shown below best represents the separation and identity of these fragments?

B

35) Polytene chromosomes of Drosophila salivary glands each consist of multiple identical DNA strands that are aligned in parallel arrays. How could these arise? A) replication followed by mitosis B) replication without separation C) meiosis followed by mitosis50 D) fertilization by multiple sperm E) special association with histone proteins

B

38) What maintains the secondary structure of a protein? A) peptide bonds B) hydrogen bonds between the amino group of one peptide bond and the carboxyl group of another peptide bond C) disulfide bonds D) hydrophobic interactions E) hydrogen bonds between the R groups

B

4) The following scientists made significant contributions to our understanding of the structure and function of DNA. Place the scientists' names in the correct chronological order, starting with the first scientist(s) to make a contribution. I. Avery, McCarty, and MacLeod II. Griffith III. Hershey and Chase IV. Meselson and Stahl V. Watson and Crick A) V, IV, II, I, III B) II, I, III, V, IV C) I, II, III, V, IV D) I, II, V, IV, III E) II, III, IV, V, I

B

40) Which level of protein structure do the α helix and the β pleated sheet represent? A) primary B) secondary C) tertiary D) quaternary E) primary, secondary, tertiary, and quaternary

B

45) The R group or side chain of the amino acid serine is -CH2-OH. The R group or side chain of the amino acid leucine is -CH2-CH-(CH3)2. Where would you expect to find these amino acids in a globular protein in aqueous solution? A) Serine would be in the interior, and leucine would be on the exterior of the globular protein. B) Leucine would be in the interior, and serine would be on the exterior of the globular protein. C) Both serine and leucine would be in the interior of the globular protein. D) Both serine and leucine would be on the exterior of the globular protein. E) Both serine and leucine would be in the interior and on the exterior of the globular protein.

B

45) Which of the following best describes the addition of nucleotides to a growing DNA chain? A) A nucleoside triphosphate is added to the 5' end of the DNA, releasing a molecule of pyrophosphate. B) A nucleoside triphosphate is added to the 3' end of the DNA, releasing a molecule of pyrophosphate. C) A nucleoside diphosphate is added to the 5' end of the DNA, releasing a molecule of phosphate. D) A nucleoside diphosphate is added to the 3' end of the DNA, releasing a molecule of phosphate. E) A nucleoside monophosphate is added to the 5' end of the DNA

B

51) Which of the following techniques uses the amino acid sequences of polypeptides to predict a protein's three-dimensional structure? A) X-ray crystallography B) bioinformatics C) analysis of amino acid sequence of small fragments D) NMR spectroscopy E) high-speed centrifugation

B

53) A typical bacterial chromosome has ~4.6 million nucleotides. This supports approximately how many genes? A) 4.6 million B) 4.4 thousand C) 45 thousand D) about 400

B

53) What is the term used for a protein molecule that assists in the proper folding of other proteins? A) tertiary protein B) chaperonin C) enzyme protein D) renaturing protein E) denaturing protein

B

54) DNAase is an enzyme that catalyzes the hydrolysis of the covalent bonds that join nucleotides together. What would first happen to DNA molecules treated with DNAase? A) The two strands of the double helix would separate. B) The phosphodiester bonds between deoxyribose sugars would be broken. C) The purines would be separated from the deoxyribose sugars. D) The pyrimidines would be separated from the deoxyribose sugars. E) All bases would be separated from the deoxyribose sugars.

B

54) Studies of nucleosomes have shown that histones (except H1) exist in each nucleosome as two kinds of tetramers: one of 2 H2A molecules and 2 H2B molecules, and the other as 2 H3 and 2 H4 molecules. Which of the following is supported by this data? A) DNA can wind itself around either of the two kinds of tetramers. B) The two types of tetramers associate to form an octamer. C) DNA has to associate with individual histones before they form tetramers. D) Only H2A can form associations with DNA molecules. E) The structure of H3 and H4 molecules is not basic like that of the other histones

B

78) 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

B) allosteric regulation.

55) When DNA is compacted by histones into 10 nm and 30 nm fibers, the DNA is unable to interact with proteins required for gene expression. Therefore, to allow for these proteins to act, the chromatin must constantly alter its structure. Which processes contribute to this dynamic activity? A) DNA supercoiling at or around H1 B) methylation and phosphorylation of histone tails C) hydrolysis of DNA molecules where they are wrapped around the nucleosome core D) accessibility of heterochromatin to phosphorylating enzymes E) nucleotide excision and reconstruction

B

55) Which of the following statements about the 5' end of a polynucleotide strand of DNA 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. E) The 5' end is the fifth position on one of the nitrogenous bases

B

56) 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. E) form the genes of higher organisms.

B

59) Which of the following are nitrogenous bases of the pyrimidine type? A) guanine and adenine B) cytosine and uracil C) thymine and guanine D) ribose and deoxyribose E) adenine and thymine

B

6) In trying to determine whether DNA or protein is the genetic material, Hershey and Chase made use of which of the following facts? A) DNA contains sulfur, whereas protein does not. B) DNA contains phosphorus, but protein does not. C) DNA contains nitrogen, whereas protein does not. D) DNA contains purines, whereas protein includes pyrimidines.44 E) RNA includes ribose, while DNA includes deoxyribose sugars.

B

60) If a cell were unable to produce histone proteins, which of the following would be a likely effect? A) There would be an increase in the amount of "satellite" DNA produced during centrifugation. B) The cell's DNA couldn't 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. E) Pseudogenes would be transcribed to compensate for the decreased protein in the cell.

B

60) Which of the following are nitrogenous bases of the purine type? A) cytosine and guanine B) guanine and adenine C) adenine and thymine D) thymine and uracil E) uracil and cytosine

B

61) Which of the following statements describes histones? A) Each nucleosome consists of two molecules of histone H1. B) Histone H1 is not present in the nucleosome bead; instead it is involved in the formation of higher-level chromatin structures. 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. E) The mass of histone in chromatin is approximately nine times the mass of DNA.

B

62) A double-stranded DNA molecule contains a total of 120 purines and 120 pyrimidines. This DNA molecule could be composed of A) 120 adenine and 120 uracil molecules. B) 120 thymine and 120 adenine molecules. C) 120 cytosine and 120 thymine molecules. D) 120 adenine and 120 cytosine molecules. E) 120 guanine and 120 thymine molecules.

B

65) If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence A) 5'TAACGT3'. B) 5'TGCAAT3'. C) 5'UAACGU3'. D) 3'UAACGU5'. E) 5'UGCAAU3'.

B

66) What is the structural feature that allows DNA to replicate? A) sugar-phosphate backbone B) complementary pairing of the nitrogenous bases C) disulfide bonding (bridging) of the two helixes D) twisting of the molecule to form an α helix E) three-component structure of the nucleotides

B

67) 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 A) is more closely related to humans than to frogs. B) is more closely related to frogs than to humans. C) evolved at about the same time as frogs, which is much earlier than primates and mammals. D) is more closely related to humans than to rats. E) is more closely related to frogs than to humans and also evolved at about the same time as frogs, which is much earlier than primates and mammals.

B

79) Which of the following statements is/are true regarding the chemical reaction illustrated in Figure 5.5? A) It is a hydrolysis reaction. B) It results in a peptide bond. C) It joins two fatty acids together. D) It is a hydrolysis reaction and it results in a peptide bond. E) It is a hydrolysis reaction, it results in a peptide bond, and it joins two fatty acids together.

B

84) Which molecule has both hydrophilic and hydrophobic properties and would be found in plasma membranes? A) 1 B) 5 C) 6 D) 12 E) 14

B

9) Which of the following investigators was/were responsible for the following discovery? Phage with labeled proteins or DNA was allowed to infect bacteria. It was shown that the DNA, but not the protein, entered the bacterial cells, and was therefore concluded to be the genetic material. A) Frederick Griffith B) Alfred Hershey and Martha Chase C) Oswald Avery, Maclyn McCarty, and Colin MacLeod D) Erwin Chargaff E) Matthew Meselson and Franklin Stahl

B

90) 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 E) 12, 13, and 15

B

91) Which of the following molecules is an amino acid with a hydrophobic R group or side chain? A) 3 B) 7 C) 8 D) 12 E) 13

B

93) A fat (or triacylglycerol) would be formed as a result of a dehydration reaction between A) one molecule of 9 and three molecules of 10. B) three molecules of 9 and one molecule of 10. C) one molecule of 5 and three molecules of 9. D) three molecules of 5 and one molecule of 9. E) one molecule of 5 and three molecules of 10.

B

98) Which of the following molecules consists of a hydrophilic "head" region and a hydrophobic "tail" region? A) 2 B) 5 C) 7 D) 9 E) 11

B

Garrod's information about the enzyme alteration resulting in alkaptonuria led to further elucidation of the same pathway in humans. Phenylketonuria (PKU) occurs when another enzyme in the pathway is altered or missing, resulting in a failure of phenylalanine (phe) to be metabolized to another amino acid: tyrosine. Tyrosine is an earlier substrate in the pathway altered in alkaptonuria. How might PKU affect the presence or absence of alkaptonuria?

B) It would have no effect, because tyrosine is also available from the diet.

When the function of the newly made polypeptide is to be secreted from the cell where it has been made, what must occur?

B) Its signal sequence must target it to the ER, from which it goes to the Golgi.

Proto-oncogenes can change into oncogenes that cause cancer. Which of the following best explains the presence of these potential time bombs in eukaryotic cells?

B) Proto-oncogenes normally help regulate cell division.

Which of the following statements best describes the termination of transcription in prokaryotes?

B) RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript.

Which of the following statements is true about stem cells?

B) Stem cells can differentiate into specialized cells.

42) In order to attach a particular amino acid to the tRNA molecule that will transport it, an enzyme, an aminoacyl-tRNA synthetase, is required, along with ATP. Initially, the enzyme has an active site for ATP and another for the amino acid, but it is not able to attach the tRNA. What must occur in order for the final attachment to occur?

B) The binding of the first two molecules must cause a 3-D change that opens another active site on the enzyme.

23) The label on a container of margarine lists "hydrogenated vegetable oil" as the major ingredient. What is the result of adding hydrogens to vegetable oil? A) The hydrogenated vegetable oil has a lower melting point. B) The hydrogenated vegetable oil stays solid at room temperature. C) The hydrogenated vegetable oil has more "kinks" in the fatty acid chains. D) The hydrogenated vegetable oil has fewer trans fatty acids. E) The hydrogenated vegetable oil is less likely to clog arteries.

B) The hydrogenated vegetable oil stays solid at room temperature.

4) For living organisms, which of the following is an important consequence of the first law of thermodynamics?

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

16) Which of the following is true for all exergonic reactions?

B) The reaction proceeds with a net release of free energy.

44) 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?

B) They can more readily encounter and phosphorylate other membrane proteins.

20) Which of the following statements concerning saturated fats is not true? A) They are more common in animals than in plants. B) They have multiple double bonds in the carbon chains of their fatty acids. C) They generally solidify at room temperature. D) They contain more hydrogen than unsaturated fats having the same number of carbon atoms. E) They are one of several factors that contribute to atherosclerosis.

B) They have multiple double bonds in the carbon chains of their fatty acids.

47) Which of the following is true of embryonic stem cells but not of adult stem cells? A) They can differentiate into many cell types. B) They make up the majority of cells of the tissue from which they are derived. C) They can continue to replicate for an indefinite period. D) They can provide enormous amounts of information about the process of gene regulation. E) One aim of using them is to provide cells for repair of diseased tissue.

B) They make up the majority of cells of the tissue from which they are derived.

26) Which of the following statements is true concerning catabolic pathways?

B) They supply energy, primarily in the form of ATP, for the cell's work.

Which of the following statements is true about protein synthesis in prokaryotes?

B) Translation can begin while transcription is still in progress.

You are given an experimental problem involving control of a geneʹs expression in the embryo of a particular species. One of your first questions is whether the geneʹs expression is controlled at the level of transcription or translation. Which of the following might best give you an answer?

B) You measure the quantity of the appropriate pre-mRNA in various cell types and find they are all the same.

Which small-scale mutation would be most likely to have a catastrophic effect on the functioning of a protein?

B) a base deletion near the start of a gene

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?

B) a deletion of two nucleotides

33) In cellular respiration, the energy for most ATP synthesis is supplied by

B) a proton gradient across a membrane.

When translating secretory or membrane proteins, ribosomes are directed to the ER membrane by

B) a signal-recognition particle that brings ribosomes to a receptor protein in the ER membrane.

11) The oxygen consumed during cellular respiration is involved directly in which process or event?

B) accepting electrons at the end of the electron transport chain

35) The primary role of oxygen in cellular respiration is to

B) act as an acceptor for electrons and hydrogen, forming water.

32) Reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as the reaction's

B) activation energy.

If a Drosophila female has a homozygous mutation for a maternal effect gene,

B) all of her offspring will show the mutant phenotype, regardless of their genotype.

In response to chemical signals, prokaryotes can do which of the following?

B) alter the level of production of various enzymes

14) How does a genomic library differ from a cDNA library? A) A genomic library contains only noncoding sequences, whereas a cDNA library contains only coding sequences. B) A genomic library varies, dependent on the cell type used to make it, whereas the content of a cDNA library does not. C) A genomic library can be made using a restriction enzyme and DNA ligase only, whereas a cDNA library requires both of these as well as reverse transcriptase and DNA polymerase. D) The genomic library can be replicated but not transcribed. E) The genomic library contains only the genes that can be expressed in the cell.

C) A genomic library can be made using a restriction enzyme and DNA ligase only, whereas a cDNA library requires both of these as well as reverse transcriptase and DNA polymerase.

Which of the following does not occur in prokaryotic eukaryotic gene expression, but does in eukaryotic gene expression?

C) A poly-A tail is added to the 3' end of an mRNA and a cap is added to the 5' end.

48) Which of the following statements describes enzyme cooperativity?

C) A substrate molecule bound to an active site of one subunit promotes substrate binding to the active site of other subunits.

53) In a mitochondrion, if the matrix ATP concentration is high, and the intermembrane space proton concentration is too low to generate sufficient proton-motive force, then

C) ATP synthase will hydrolyze ATP and pump protons into the intermembrane space.

52) Brown fat cells produce a protein called thermogenin in their mitochondrial inner membrane. Thermogenin is a channel for facilitated transport of protons across the membrane. What will occur in the brown fat cells when they produce thermogenin?

C) ATP synthesis will decrease, and heat generation will increase.

The nitrogenous base adenine is found in all members of which group?

C) ATP, RNA, and DNA

29) A number of systems for pumping ions across membranes are powered by ATP. Such ATP-powered pumps are often called ATPases although they don't 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?

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

A part of the promoter, called the TATA box, is said to be highly conserved in evolution. Which of the following might this illustrate?

C) Any mutation in the sequence is selected against.

82) In which step in Figure 9.1 is an inorganic phosphate added to the reactant?

C) C

83) Which step in Figure 9.1 is a redox reaction?

C) C

In a series of experiments, the enzyme Dicer has been inactivated in cells from various vertebrates, and the centromere is abnormally formed from chromatin. Which of the following is most likely to occur?

C) Centromeres will be euchromatic rather than heterochromatic and the cells will soon die in culture.

24) Which of the following seals the sticky ends of restriction fragments to make recombinant DNA? A) restriction enzymes B) gene cloning C) DNA ligase D) gel electrophoresis E) reverse transcriptase

C) DNA ligase

Gene expression might be altered at the level of post-transcriptional processing in eukaryotes rather than prokaryotes because of which of the following?

C) Eukaryotic exons may be spliced in alternative patterns.

5) What is the most logical sequence of steps for splicing foreign DNA into a plasmid and inserting the plasmid into a bacterium? I. Transform bacteria with recombinant DNA molecule. II. Cut the plasmid DNA using restriction enzymes. III. Extract plasmid DNA from bacterial cells. IV. Hydrogen-bond the plasmid DNA to nonplasmid DNA fragments. V. Use ligase to seal plasmid DNA to nonplasmid DNA. A) I, II, IV, III, V B) II, III, V, IV, I C) III, II, IV, V, I D) III, IV, V, I, II E) IV, V, I, II, III

C) III, II, IV, V, I

51) In liver cells, the inner mitochondrial membranes are about five times the area of the outer mitochondrial membranes. What purpose must this serve?

C) It increases the surface for oxidative phosphorylation.

What is the effect of a nonsense mutation in a gene?

C) It introduces a premature stop codon into the mRNA.

22) For the hydrolysis of ATP to ADP + i, the free energy change is -7.3 kcal/mol under standard conditions (1 M concentration of both reactants and products). In the cellular environment, however, the free energy change is about -13 kcal/mol. What can we conclude about the free energy change for the formation of ATP from ADP and i under cellular conditions?

C) It is about +13 kcal/mol.

Which of the following is true of transcription in domain Archaea?

C) It is roughly simultaneous with translation.

66) When an individual is exercising heavily and when the muscle becomes oxygen-deprived, muscle cells convert pyruvate to lactate. What happens to the lactate in skeletal muscle cells?

C) It is taken to the liver and converted back to pyruvate.

18) 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?

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

17) In addition to ATP, what are the end products of glycolysis?

C) NADH and pyruvate

Suppose that a mutation alters the formation of a tRNA such that it still attaches to the same amino acid (phe) but its anticodon loop has the sequence AAU that binds to the mRNA codon UUA (that usually specifies leucine leu).

C) One mutated tRNA molecule will be relatively inconsequential because it will compete with many "normal" ones.

22) The major advantage of using artificial chromosomes such as YACs and BACs for cloning genes is that A) plasmids are unable to replicate in cells. B) only one copy of a plasmid can be present in any given cell, whereas many copies of a YAC or BAC can coexist in a single cell. C) YACs and BACs can carry much larger DNA fragments than ordinary plasmids can. D) YACs and BACs can be used to express proteins encoded by inserted genes, but plasmids cannot. E) all of the above

C) YACs and BACs can carry much larger DNA fragments than ordinary plasmids can.

18) A student wishes to clone a sequence of DNA of ~200 kb. Which vector would be appropriate? A) a plasmid B) a typical bacteriophage C) a BAC D) a plant virus E) a large polypeptide

C) a BAC

Of the following, which is the most current description of a gene?

C) a DNA sequence that is expressed to form a functional product: either RNA or polypeptide

In order for a eukaryotic gene to be engineered into a bacterial colony to be expressed, what must be included in addition to the coding exons of the gene?

C) a bacterial promoter sequence

What is an organic, non-protein component of an enzyme called?

C) a coenzyme

50) Which of the following is an example of cooperativity?

C) a molecule binding at one unit of a tetramer, allowing faster binding at each of the other three

1) Which enzyme was used to produce the molecule in Figure 20.1? A) ligase B) transcriptase C) a restriction enzyme D) RNA polymerase E) DNA polymerase

C) a restriction enzyme

A series of enzymes catalyze the reaction 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. 73) What is substance X?

C) a substrate

45) Which of the following problems with animal cloning might result in premature death of the clones? A) use of pluripotent instead of totipotent stem cells B) use of nuclear DNA as well as mtDNA C) abnormal regulation due to variant methylation D) the indefinite replication of totipotent stem cells E) abnormal immune function due to bone marrow dysfunction

C) abnormal regulation due to variant methylation

A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. She tried decreasing the amount of methylation enzymes in the embryonic stem cells

C) abnormalities of mouse embryos

76) Where do the catabolic products of fatty acid breakdown enter into the citric acid cycle?

C) acetyl CoA

This binds to a site in the DNA far from the promoter to stimulate transcription:

C) activator

How can one increase the rate of a chemical reaction?

C) add a catalyst

36) DNA microarrays have made a huge impact on genomic studies because they A) can be used to eliminate the function of any gene in the genome. B) can be used to introduce entire genomes into bacterial cells. C) allow the expression of many or even all of the genes in the genome to be compared at once. D) allow physical maps of the genome to be assembled in a very short time. E) dramatically enhance the efficiency of restriction enzymes.

C) allow the expression of many or even all of the genes in the genome to be compared at once.

Altering patterns of gene expression in prokaryotes would most likely serve the organismʹs survival in which of the following ways?

C) allowing the organism to adjust to changes in environmental conditions

25) Which of the following is most similar in structure to ATP?

C) an RNA nucleotide

22) Which kind of metabolic poison would most directly interfere with glycolysis?

C) an agent that closely mimics the structure of glucose but is not metabolized

10) A principal problem with inserting an unmodified mammalian gene into a bacterial plasmid, and then getting that gene expressed in bacteria, is that A) prokaryotes use a different genetic code from that of eukaryotes. B) bacteria translate polycistronic messages only. C) bacteria cannot remove eukaryotic introns. D) bacterial RNA polymerase cannot make RNA complementary to mammalian DNA. E) bacterial DNA is not found in a membrane-bounded nucleus and is therefore incompatible with mammalian DNA.

C) bacteria cannot remove eukaryotic introns.

55) How might an amino acid change at a site distant from the active site of the enzyme alter the enzyme's substrate specificity?

C) by changing the shape of the protein

Tumor suppressor genes

C) can encode proteins that promote DNA repair or cell-cell adhesion.

45) When you have a severe fever, what grave consequence may occur if the fever is not controlled?

C) change in the tertiary structure of your enzymes

39) Increasing the substrate concentration in an enzymatic reaction could overcome which of the following?

C) competitive inhibition

2) Assume that you are trying to insert a gene into a plasmid. Someone gives you a preparation of genomic DNA that has been cut with restriction enzyme X. The gene you wish to insert has sites on both ends for cutting by restriction enzyme Y. You have a plasmid with a single site for Y, but not for X. Your strategy should be to A) insert the fragments cut with X directly into the plasmid without cutting the plasmid. B) cut the plasmid with restriction enzyme X and insert the fragments cut with Y into the plasmid. C) cut the DNA again with restriction enzyme Y and insert these fragments into the plasmid cut with the same enzyme.

C) cut the DNA again with restriction enzyme Y and insert these fragments into the plasmid cut with the same enzyme.

7) What is the chemical reaction mechanism by which cells make polymers from monomers? A) phosphodiester linkages B) hydrolysis C) dehydration reactions D) ionic bonding of monomers E) the formation of disulfide bridges between monomers

C) dehydration reaction

In an experimental situation, a student researcher inserts an mRNA molecule into a eukaryotic cell after he has removed its 5' cap and poly-A tail. Which of the following would you expect him to find?

D) The molecule is digested by exonucleases since it is no longer protected at the 5' end.

30) There are 20 different amino acids. What makes one amino acid different from another? A) different side chains (R groups) attached to a carboxyl carbon B) different side chains (R groups) attached to the amino groups C) different side chains (R groups) attached to an α carbon D) different structural and optical isomers E) different asymmetric carbons

C) different side chains (R groups) attached to an α carbon

These genes are expressed by the mother, and their products are deposited into the developing egg:

C) egg-polarity genes

6) Bacteria containing recombinant plasmids are often identified by which process? A) examining the cells with an electron microscope B) using radioactive tracers to locate the plasmids C) exposing the bacteria to an antibiotic that kills cells lacking the resistant plasmid D) removing the DNA of all cells in a culture to see which cells have plasmids E) producing antibodies specific for each bacterium containing a recombinant plasmid

C) exposing the bacteria to an antibiotic that kills cells lacking the resistant plasmid

28) Restriction fragments of DNA are typically separated from one another by which process? A) filtering B) centrifugation C) gel electrophoresis D) PCR E) electron microscopy

C) gel electrophoresis

102) Which metabolic pathway is common to both fermentation and cellular respiration of a glucose molecule?

C) glycolysis

If you were to observe the activity of methylated DNA, you would expect it to

C) have turned off or slowed down the process of transcription.

19) Humans can digest starch but not cellulose because A) the monomer of starch is glucose, while the monomer of cellulose is galactose. B) humans have enzymes that can hydrolyze the β glycosidic linkages of starch but not the α glycosidic linkages of cellulose. C) humans have enzymes that can hydrolyze the α glycosidic linkages of starch but not the β glycosidic linkages of cellulose. D) humans harbor starch-digesting bacteria in the digestive tract. E) the monomer of starch is glucose, while the monomer of cellulose is glucose with a nitrogen-containing group.

C) humans have enzymes that can hydrolyze the α glycosidic linkages of starch but not the β glycosidic linkages of cellulose.

What type of bonding is responsible for maintaining the shape of the tRNA molecule?

C) hydrogen bonding between base pairs

54) In experimental tests of enzyme evolution, where a gene encoding an enzyme is subjected to multiple cycles of random mutagenesis and selection for altered substrate specificity, the resulting enzyme had multiple amino acid changes associated with altered substrate specificity. Where in the enzyme were these amino acid changes located?

C) in or near the active site and at surface sites away from the active site

54) In prokaryotes, the respiratory electron transport chain is located

C) in the plasma membrane.

42) Which of the following techniques used to analyze gene function depends on the specificity of DNA base complementarity? A) Northern blotting B) use of RNAi C) in vitro mutagenesis D) in situ hybridization E) restriction fragment analysis

C) in vitro mutagenesis

34) Which of the following procedures would produce RFLPs? A) incubating a mixture of single-stranded DNA from two closely related species B) incubating DNA nucleotides with DNA polymerase C) incubating DNA with restriction enzymes D) incubating RNA with DNA nucleotides and reverse transcriptase E) incubating DNA fragments with "sticky ends" with ligase

C) incubating DNA with restriction enzymes

During DNA replication,

C) methylation of the DNA is maintained because methylation enzymes act at DNA sites where one strand is already methylated and thus correctly methylates daughter strands after replication.

32) Where are the proteins of the electron transport chain located?

C) mitochondrial inner membrane

37) During aerobic respiration, H2O is formed. Where does the oxygen atom for the formation of the water come from?

C) molecular oxygen (O2)

Absence of bicoid mRNA from a Drosophila egg leads to the absence of anterior larval body parts and mirror-image duplication of posterior parts. This is evidence that the product of the bicoid gene

C) normally leads to formation of head structures.

62) One function of both alcohol fermentation and lactic acid fermentation is to

C) oxidize NADH to NAD+.

6) When a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, the molecule becomes

C) oxidized.

A boulder rolling down a hill is an example of a change from _______ energy to ________ energy.

C) potential; kinetic

A mutation in this section of DNA could influence the binding of RNA polymerase to the DNA:

C) promoter

103) In mitochondria, exergonic redox reactions

C) provide the energy that establishes the proton gradient.

7) When a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a proton), the molecule becomes

C) reduced.

16) During glycolysis, when each molecule of glucose is catabolized to two molecules of pyruvate, most of the potential energy contained in glucose is

C) retained in the two pyruvates.

11) A gene that contains introns can be made shorter (but remain functional) for genetic engineering purposes by using A) RNA polymerase to transcribe the gene. B) a restriction enzyme to cut the gene into shorter pieces. C) reverse transcriptase to reconstruct the gene from its mRNA. D) DNA polymerase to reconstruct the gene from its polypeptide product. E) DNA ligase to put together fragments of the DNA that codes for a particular polypeptide.

C) reverse transcriptase to reconstruct the gene from its mRNA.

One of the hopes for use of recent knowledge gained about non-coding RNAs lies with the possibilities for their use in medicine. Of the following scenarios for future research, which would you expect to gain most from RNAs?

C) targeting siRNAs to disable the expression of an allele associated with autosomal dominant disease

23) In the late 1950s, Meselson and Stahl grew bacteria in a medium containing "heavy" nitrogen(15N) and then transferred them to a medium containing 14N. Which of the results in Figure 16.1 would be expected after one round of DNA replication in the presence of 14N? A) Only 15N DNA B) 15N DNA & 14N DNA C) Only 14N DNA D) 14N-15N hybrid DNA E) 14N-15N hybrid DNA & 14N DNA

D

25) Once the pattern found after one round of replication was observed, 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 semi-conservative. D) Replication is not conservative. E) Replication is neither dispersive nor conservative.

D

31) The enzyme telomerase solves the problem of replication at the ends of linear chromosomes by which method? A) adding a single 5' cap structure that resists degradation by nucleases B) causing specific double strand DNA breaks that result in blunt ends on both strands C) causing linear ends of the newly replicated DNA to circularize D) adding numerous short DNA sequences such as TTAGGG, which form a hairpin turn E) adding numerous GC pairs which resist hydrolysis and maintain chromosome integrity

D

34) 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) 3' G C C T A G G 5' C) 5' A C G T T A G G 3' D) 5' A C G U U A G G 3' E) 5' G C C U A G G 3'

D

39) Which of the following removes the RNA nucleotides from the primer and adds equivalent DNA nucleotides to the 3' end of Okazaki fragments? A) helicase B) DNA polymerase III C) ligase D) DNA polymerase I E) primase

D

39) Which type of interaction stabilizes the α helix and the β pleated sheet structures of proteins? A) hydrophobic interactions B) disulfide bonds C) ionic bonds D) hydrogen bonds E) peptide bonds

D

43) What type of covalent bond between amino acid side chains (R groups) functions in maintaining a polypeptide's specific three-dimensional shape? A) ionic bond B) hydrophobic interaction C) van der Waals interaction D) disulfide bond E) hydrogen bond

D

46) 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 only B) Parkinson's only C) diabetes mellitus only D) Alzheimer's and Parkinson's only E) Alzheimer's, Parkinson's, and diabetes mellitus

D

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

D

5) After mixing a heat-killed, phosphorescent strain of bacteria with a living non-phosphorescent strain, you discover that some of the living cells are now phosphorescent. Which observations would provide the best evidence that the ability to fluoresce is a heritable trait? A) DNA passed from the heat-killed strain to the living strain. B) Protein passed from the heat-killed strain to the living strain. C) The phosphorescence in the living strain is especially bright. D) Descendants of the living cells are also phosphorescent. E) Both DNA and protein passed from the heat-killed strain to the living strain.

D

50) In a normal cellular protein, where would you expect to find a hydrophobic amino acid like valine? A) in the interior of the folded protein, away from water B) on the exterior surface of the protein, interacting with water C) in the transmembrane portion interacting with lipid fatty acid chains D) in the interior of the folded protein, away from water, or in a transmembrane portion interacting with lipid fatty acid chains E) anywhere in the protein, with equal probability

D

50) Individuals with the disorder xeroderma pigmentosum are hypersensitive to sunlight. This occurs because their cells have which impaired ability? A) They cannot replicate DNA. B) They cannot undergo mitosis. C) They cannot exchange DNA with other cells. D) They cannot repair thymine dimers. E) They do not recombine homologous chromosomes during meiosis.

D

51) Which would you expect of a eukaryotic cell lacking telomerase? A) a high probability of becoming cancerous B) production of Okazaki fragments C) inability to repair thymine dimers53 D) a reduction in chromosome length E) high sensitivity to sunlight

D

57) In prophase I of meiosis in female Drosophila, studies have shown that there is phosphorylation of an amino acid in the tails of histones. A mutation in flies that interferes with this process results in sterility. Which of the following is the most likely hypothesis? A) These oocytes have no histones. B) Any mutation during oogenesis results in sterility. C) Phosphorylation of all proteins in the cell must result. D) Histone tail phosphorylation prohibits chromosome condensation. E) Histone tails must be removed from the rest of the histones.

D

58) In a linear eukaryotic chromatin sample, which of the following strands is looped into domains by scaffolding? A) DNA without attached histones B) DNA with H1 only C) the 10 nm chromatin fiber D) the 30 nm chromatin fiber E) the metaphase chromosome

D

59) Which of the following statements describes the eukaryotic chromosome? A) It is composed of DNA alone. B) The nucleosome is its most basic functional subunit. C) The number of genes on each chromosome is different in different cell types of an organism. D) It consists of a single linear molecule of double-stranded DNA. E) Active transcription occurs on heterochromatin.

D

68) Which of the following is an example of hydrolysis? A) the reaction of two monosaccharides, forming a disaccharide with the release of water B) the synthesis of two amino acids, forming a peptide with the release of water C) the reaction of a fat, forming glycerol and fatty acids with the release of water D) the reaction of a fat, forming glycerol and fatty acids with the consumption of water E) the synthesis of a nucleotide from a phosphate, a pentose sugar, and a nitrogenous base with the production of a molecule of water

D

28) When ATP releases some energy, it also releases inorganic phosphate. What purpose does this serve (if any) in the cell?

D) The phosphate may be incorporated into any molecule that contains phosphate.

75) Which of the following statements is true regarding the molecule illustrated in Figure 5.2? A) It is a saturated fatty acid. B) A diet rich in this molecule may contribute to atherosclerosis. C) Molecules of this type are usually liquid at room temperature. D) It is a saturated fatty acid and a diet rich in this molecule may contribute to atherosclerosis. E) It is a saturated fatty acid, a diet rich in this molecule may contribute to atherosclerosis, and molecules of this type are usually liquid at room temperature

D

85) Which of the following combinations could be linked together to form a nucleotide? A) 1, 2, and 11 B) 3, 7, and 8 C) 5, 9, and 10 D) 11, 12, and 13 E) 12, 14, and 15

D

94) Which of the following molecules could be joined together by a phosphodiester type of covalent bond? A) 3 and 4 B) 3 and 8 C) 6 and 15 D) 11 and 12 E) 11 and 13

D

95) Which of the following molecules is the pentose sugar found in RNA? A) 1 B) 4 C) 6 D) 12 E) 13

D

31) What fraction of the carbon dioxide exhaled by animals is generated by the reactions of the citric acid cycle, if glucose is the sole energy source?

D) 2/3

90) Starting with citrate, which of the following combinations of products would result from three acetyl CoA molecules entering the citric acid cycle (see Figure 9.2)?

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

What are the products following the hydrolysis of ATP?

D) ADP + Pi

99) After the further agitation of the membrane vesicles, what must be lost from the membrane?

D) ATP synthase, in whole or in part

The bicoid gene product is normally localized to the anterior end of the embryo. If large amounts of the product were injected into the posterior end as well, which of the following would occur?

D) Anterior structures would form in both sides of the embryo.

5) 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?

D) As a consequence of growing, organisms cause a greater increase in entropy in their environment than the decrease in entropy associated with their growth.

If she moves the promoter for the lac operon to the region between the beta galactosidase gene and the permease gene, which of the following would be likely?

D) Beta galactosidase will be produced.

51) Which of the following are probably siblings? A) A and B B) A and C C) A and D D) C and D E) B and D

D) C and D

8) Which of the following statements is representative of the second law of thermodynamics?

D) Cells require a constant input of energy to maintain their high level of organization.

Two potential devices that eukaryotic cells use to regulate transcription are

D) DNA methylation and histone acetylation.

Which of the following provides some evidence that RNA probably evolved before DNA?

D) DNA polymerase uses primer, usually made of RNA.

Which was defined as a measure of disorder, or randomness?

D) Entropy

40) Which of the following is true of enzymes?

D) Enzymes increase the rate of chemical reaction by lowering activation energy barriers.

7) Which of the following statements is a logical consequence of the second law of thermodynamics?

D) Every chemical reaction must increase the total entropy of the universe.

CML (chronic myelogenous leukemia) results from a translocation between human chromosomes 9 and 22. The resulting chromosome 22 is significantly shorter than the usual, and it is known as a Philadelphia (Ph') chromosome. The junction at the site of the translocation causes over-expression of a thymine kinase receptor. A new drug (Gleevec or imatinib) has been found to inhibit the disease if the patient is treated early. 58) Which of the following would be a reasonably efficient technique for confirming the diagnosis of CML? A) searching for the number of telomeric sequences on chromosome 22 B) looking for a Ph' chromosome in a peripheral blood smear C) enzyme assay for thymine kinase activity D) FISH study to determine the chromosomal location of all chromosome 22 q fragments E) identification of the disease phenotype in review of the patient's records

D) FISH study to determine the chromosomal location of all chromosome 22 q fragments

101) The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the

D) H+ concentration across the membrane holding ATP synthase.

Which of the following is not true of a codon?

D) It extends from one end of a tRNA molecule.

27) When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated?

D) It is lost to the environment.

Why might a point mutation in DNA make a difference in the level of protein's activity?

D) It might substitute an amino acid in the active site.

How does active CAP induce expression of the genes of the lactose operon?

D) It stimulates the binding of RNA polymerase to the promoter.

Which of the following describes the function of an enzyme known as Dicer?

D) It trims small double-stranded RNAs into molecules that can block translation.

13) Which of the following is true of metabolism in its entirety in all organisms?

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

92) Figure 9.3 shows the electron transport chain. Which of the following is the combination of substances that is initially added to the chain?

D) NADH, FADH2, and O2

The researcher continues to study the reactions of the embryo to these new proteins and you hypothesize that he is most likely to see which of the following (while embryonic genes are still not being expressed)?

D) Spatial axes (anterior → posterior, etc.) begin to be determined.

Which of the following metabolic terms refers to synthetic processes, which consumes energy?

D) Synthebolism

57) Which of the following is one of the technical reasons why gene therapy is problematic? A) Most cells with an engineered gene do not produce gene product. B) Most cells with engineered genes overwhelm other cells in a tissue. C) Cells with transferred genes are unlikely to replicate. D) Transferred genes may not have appropriately controlled activity. E) mRNA from transferred genes cannot be translated.

D) Transferred genes may not have appropriately controlled activity

In the 1920s Muller discovered that X-rays caused mutation in Drosophila. In a related series of experiments in the 1940s, Charlotte Auerbach discovered that chemicals-she used nitrogen mustards-have a similar effect. A new chemical food additive is developed by a cereal manufacturer. Why do we test for its ability to induce mutation?

D) We want to prevent any increase in mutation frequency.

17) Chemical equilibrium is relatively rare in living cells. Which of the following could be an example of a reaction at chemical equilibrium in a cell?

D) a chemical reaction in which both the reactants and products are not being produced or used in any active metabolic pathway

11) Which of the following is an example of potential rather than kinetic energy?

D) a molecule of glucose

The most commonly occurring mutation in people with cystic fibrosis is a deletion of a single codon. This results in

D) a polypeptide missing an amino acid.

20) Sequencing an entire genome, such as that of C. elegans, a nematode, is most important because A) it allows researchers to use the sequence to build a "better" nematode, resistant to disease. B) it allows research on a group of organisms we do not usually care much about. C) the nematode is a good animal model for trying out cures for viral illness. D) a sequence that is found to have a particular function in the nematode is likely to have a closely related function in vertebrates. E) a sequence that is found to have no introns in the nematode genome is likely to have acquired the introns from higher organisms.

D) a sequence that is found to have a particular function in the nematode is likely to have a closely related function in vertebrates

Which of the following mutations is most likely to cause a phenotypic change?

D) a single nucleotide deletion in an exon coding for an active site

What is meant by the term "allosteric site"?

D) a site on an enzyme distant from the active site, but able to affect the active site

Which of the following nucleotide triplets best represents a codon?

D) a triplet in the same reading frame as an upstream AUG

25) Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of a carbon (CO2) from one molecule of pyruvate?

D) acetyl CoA

96) These three steps result in the formation of

D) acetyl CoA, NADH, H+, and CO2.

26) Which modifications of fatty acids will best keep triglycerides solid at warmer temperatures? A) creating cis double bonds to the fatty acids B) adding hydrogens to the fatty acids C) creating trans double bonds to the fatty acids D) adding hydrogens and trans double bonds to the fatty acids E) adding cis double bonds and trans double bonds to the fatty acids

D) adding hydrogens and trans double bonds to the fatty acids

48) Chemiosmotic ATP synthesis (oxidative phosphorylation) occurs in

D) all respiring cells, both prokaryotic and eukaryotic, using either oxygen or other electron acceptors.

If a particular operon encodes enzymes for making an essential amino acid and is regulated like the trp operon, then the

D) amino acid acts as a corepressor.

49) Allosteric enzyme regulation is usually associated with

D) an enzyme with more than one subunit.

15) Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified? A) as a pentose B) as a hexose C) as a monosaccharide D) as a disaccharide E) as a polysaccharide

D) as a disaccaride

Steroid hormones produce their effects in cells by

D) binding to intracellular receptors and promoting transcription of specific genes.

41) 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(n)

D) cofactor necessary for enzyme activity.

94) Which of the protein complexes labeled with Roman numerals in Figure 9.3 will transfer electrons to O2?

D) complex IV

What would occur if the repressor of an inducible operon were mutated so it could not bind the operator?

D) continuous transcription of the operonʹs genes

41) When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the result is the

D) creation of a proton-motive force.

38) In chemiosmotic phosphorylation, what is the most direct source of energy that is used to convert ADP + i to ATP?

D) energy released from movement of protons through ATP synthase, down the electrochemical gradient

6) Whenever energy is transformed, there is always an increase in the

D) entropy of the universe.

Genomic imprinting, DNA methylation, and histone acetylation are all examples of

D) epigenetic phenomena.

Differentiation of cells is not easily reversible because it involves

D) frameshift mutations and inversions.

44) In 1997, Dolly the sheep was cloned. Which of the following processes was used? A) use of mitochondrial DNA from adult female cells of another ewe B) replication and dedifferentiation of adult stem cells from sheep bone marrow C) separation of an early stage sheep blastula into separate cells, one of which was incubated in a surrogate ewe D) fusion of an adult cell's nucleus with an enucleated sheep egg, followed by incubation in a surrogate E) isolation of stem cells from a lamb embryo and production of a zygote equivalent

D) fusion of an adult cell's nucleus with an enucleated sheep egg, followed by incubation in a surrogate

27) Which of the following separates molecules by movement due to size and electrical charge? A) restriction enzymes B) gene cloning C) DNA ligase D) gel electrophoresis E) reverse transcriptase

D) gel electrophoresis

52) Gene therapy A) has proven to be beneficial to HIV patients. B) involves replacement of a defective allele in sex cells. C) cannot be used to correct genetic disorders. D) had apparent success in treating disorders involving bone marrow cells. E) is a widely accepted procedure.

D) had apparent success in treating disorders involving bone marrow cells.

21) A molecule that is phosphorylated

D) has an increased chemical potential energy; it is primed to do cellular work.

Muscle cells and nerve cells in one species of animal owe their differences in structure to

D) having different genes expressed.

73) Even though plants carry on photosynthesis, plant cells still use their mitochondria for oxidation of pyruvate. When and where will this occur?

D) in all cells all the time

Use the following information to answer the questions below. A eukaryotic gene has "sticky ends" produced by the restriction endonuclease EcoRI. The gene is added to a mixture containing EcoRI and a bacterial plasmid that carries two genes conferring resistance to ampicillin and tetracycline. The plasmid has one recognition site for EcoRI located in the tetracycline resistance gene. This mixture is incubated for several hours, exposed to DNA ligase, and then added to bacteria growing in nutrient broth. The bacteria are allowed to grow overnight and are streaked on a plate using a technique that produces isolated colonies that are clones of the original. Samples of these colonies are then grown in four different media: nutrient broth plus ampicillin, nutrient broth plus tetracycline, nutrient broth plus ampicillin and tetracycline, and nutrient broth without antibiotics. 7) Bacteria that contain the plasmid, but not the eukaryotic gene, would grow A) in the nutrient broth plus ampicillin, but not in the broth containing tetracycline. B) only in the broth containing both antibiotics. C) in the broth containing tetracycline, but not in the broth containing ampicillin. D) in all four types of broth. E) in the nutrient broth without antibiotics o

D) in all four types of broth.

One hereditary disease in humans, called xeroderma pigmentosum (XP), makes homozygous individuals exceptionally susceptible to UV-induced mutation damage in the cells of exposed tissue, especially skin. Without extraordinary avoidance of sunlight exposure, patients soon succumb to numerous skin cancers. Which of the following best describes this phenomenon?

D) inherited inability to repair UV-induced mutation

42) Where is ATP synthase located in the mitochondrion?

D) inner membrane

18) Which of the following is true of cellulose? A) It is a polymer composed of enantiomers of glucose. B) It is a storage polysaccharide for energy in plant cells. C) It is digestible by bacteria in the human gut. D) It is a major structural component of plant cell walls. E) It is a polymer composed of enantiomers of glucose, it is a storage polysaccharide for energy in plant cells, it is digestible by bacteria in the human gut, and it is a major structural component of plant cell walls.

D) it is a major structural component of plant cell walls

38) Mutations that result in single amino acid substitutions in an enzyme

D) may affect the physicochemical properties of the enzyme such as its optimal temperature and pH.

39) Energy released by the electron transport chain is used to pump H+ into which location in eukaryotic cells?

D) mitochondrial intermembrane space

These genes form gradients and help establish the axes and other features of an embryo:

D) morphogens

At the beginning of this century there was a general announcement regarding the sequencing of the human genome and the genomes of many other multicellular eukaryotes. There was surprise expressed by many that the number of protein-coding sequences is much smaller than they had expected. Which of the following accounts for most of the rest?

D) non-protein coding DNA that is transcribed into several kinds of small RNAs with biological function

Transcription factors in eukaryotes usually have DNA binding domains as well as other domains also specific for binding. In general, which of the following would you expect many of them to be able to bind?

D) other transcription factors

This can inhibit transcription by blocking the binding of positively acting transcription factors to the DNA:

D) repressor

This protein is produced by a regulatory gene:

D) repressor

Transcription in eukaryotes requires which of the following in addition to RNA polymerase?

D) several transcription factors (TFs)

The lactose operon is likely to be transcribed when

D) the cyclic AMP and lactose levels are both high within the cell.

How does feedback inhibition work?

D) the final product of a biochemical pathway inhibits the first enzyme in the pathway

The incidence of cancer increases dramatically in older humans because

D) the longer we live, the more mutations we accumulate.

40) The direct energy source that drives ATP synthesis during respiratory oxidative phosphorylation in eukaryotic cells is

D) the proton-motive force across the inner mitochondrial membrane.

1) Humans and mice differ because A) their cells have different small organic molecules. B) their cells make different types of large biological molecules. C) their cells make different types of lipids. D) their cells have some differences in the sequence of nucleotides in their nucleic acids. E) their cells make different types of proteins.

D) their cells have some differences in the sequence of nucleotides in their nucleic acids.

12) Why are yeast cells frequently used as hosts for cloning? A) they easily form colonies B) they can remove exons from mRNA. C) they do not have plasmids. D) they are eukaryotic cells E) only yeast cells allow the gene to be cloned

D) they are eukaryotic cells

3) What is the enzymatic function of restriction enzymes? A) to add new nucleotides to the growing strand of DNA B) to join nucleotides during replication C) to join nucleotides during transcription D) to cleave nucleic acids at specific sites E) to repair breaks in sugar-phosphate backbones

D) to cleave nucleic acids at specific sites

Which of the following is a function of a signal peptide?

D) to translocate polypeptides across the ER membrane

87) Carbon skeletons for amino acid biosynthesis are supplied by intermediates of the citric acid cycle. Which intermediate would supply the carbon skeleton for synthesis of a five-carbon amino acid (see Figure 9.2)?

D) α-ketoglutarate

10) Which of the following polymers contain nitrogen? A) starch B) glycogen C) cellulose D) chitin E) amylopectin

D. chitin

DNA Region

DNA is organized into chromosomes; each segment of DNA that codes for a trait is a gene. In a eukaryotic cell, the DNA region is the nucleus.

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?

Darwin's explanation of natural selection.

A scientist discovers a DNA-based test for one allele of a particular gene. This and only this allele, if homozygous, produces an effect that results in death at or about the time of birth. Of the following, which is the best use of this discovery?

Design a test for identifying heterozygous carriers of the allele.

"Tertiary" structure of protein

Determined by interactions between R groups rather than interactions between backbone constituents.

The individual with AaBbCCDdEE can make many kinds of gametes. Which of the following is the major reason?

Different possible alignments of chromosomes.

Genes

Discrete units of hereditary information consisting of a special nucleotide sequence in DNA (or RNA, in some viruses)

Lipids

Do not form polymers. No affinity for water, they're hydrophobic because they consist of hydrocarbons. Nonpolar covalent bonds.

Asexual Reproduction

Doesn't involve gametes

Taxonomic Levels of Organization

Domain - Kingdom - Phylum - Class - Order - Family - Genus - Species

Sturtevant provided genetic evidence for the existence of four pairs of chromosomes in Drosophila in which of these ways?

Drosophila genes cluster into four distinct groups of linked genes

22) 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) Radioactive thymine would pair with nonradioactive guanine. E) DNA in both daughter cells would be radioactive.

E

3) What does transformation involve in bacteria? A) the creation of a strand of DNA from an RNA molecule B) the creation of a strand of RNA from a DNA molecule C) the infection of cells by a phage DNA molecule D) the type of semiconservative replication shown by DNA E) assimilation of external DNA into a cell

E

32) The DNA of telomeres has been found to be highly conserved throughout the evolution of eukaryotes. What does this most probably reflect? A) the inactivity of this DNA B) the low frequency of mutations occurring in this DNA C) that new evolution of telomeres continues D) that mutations in telomeres are relatively advantageous E) that the critical function of telomeres must be maintained

E

36) How many different kinds of polypeptides, each composed of 12 amino acids, could be synthesized using the 20 common amino acids? A) 412 B) 1220 C) 240 D) 20 E) 2012

E

36) To repair a thymine dimmer by nucleotide excision repair, in which order do the necessary enzymes act? A) exonuclease, DNA polymerase III, RNA primase B) helicase, DNA polymerase I, DNA ligase C) DNA ligase, nuclease, helicase D) DNA polymerase I, DNA polymerase III, DNA ligase E) endonuclease, DNA polymerase I, DNA ligase

E

41) The amino acids of the protein keratin are arranged predominantly in an α helix. This secondary structure is stabilized by A) covalent bonds. B) peptide bonds. C) ionic bonds. D) polar bonds. E) hydrogen bonds.

E

42) Which of the following synthesizes short segments of RNA? A) helicase B) DNA polymerase III C) ligase D) DNA polymerase I E) primase

E

46) A new DNA strand elongates only in the 5' to 3' direction because A) DNA polymerase begins adding nucleotides at the 5' end of the template. B) Okazaki fragments prevent elongation in the 3' to 5' direction. C) the polarity of the DNA molecule prevents addition of nucleotides at the 3' end. D) replication must progress toward the replication fork. E) DNA polymerase can only add nucleotides to the free 3' end.

E

47) Changing a single amino acid in a protein consisting of 325 amino acids would A) alter the primary structure of the protein, but not its tertiary structure or function. B) cause the tertiary structure of the protein to unfold. C) always alter the biological activity or function of the protein. D) always alter the primary structure of the protein and disrupt its biological activity. E) always alter the primary structure of the protein, sometimes alter the tertiary structure of the protein, and affect its biological activity.

E

48) Normal hemoglobin is a tetramer, consisting of two molecules of β hemoglobin and two molecules of α hemoglobin. 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) altered primary structure. B) altered secondary structure. C) altered tertiary structure. D) altered quaternary structure. E) altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered.

E

49) What methods may be used to elucidate the structures of purified proteins? A) X-ray crystallography B) bioinformatics C) analysis of amino acid sequence of small fragments D) NMR spectroscopy E) both X-ray crystallography and NMR spectroscopy

E

63) The difference between the sugar in DNA and the sugar in RNA is that the sugar in DNA A) is a six-carbon sugar and the sugar in RNA is a five-carbon sugar. B) can form a double-stranded molecule. C) is an aldehyde sugar and the sugar in RNA is a keto sugar. D) is in the α configuration and the sugar in RNA is in the β configuration. E) contains one less oxygen atom.

E

69) If cells are grown in a medium containing radioactive 32P-labeled phosphate, which of these molecules will be labeled? A) phospholipids B) nucleic acids C) proteins D) amylose E) both phospholipids and nucleic acids

E

7) For a science fair project, two students decided to repeat the Hershey and Chase experiment, with modifications. They decided to label the nitrogen of the DNA, rather than the phosphate. They reasoned that each nucleotide has only one phosphate and two to five nitrogens. Thus, labeling the nitrogens 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) Avery et al. have already concluded that this experiment showed inconclusive results. D) Although there are more nitrogens in a nucleotide, labeled phosphates actually have 16 extra neutrons; therefore, they are more radioactive. E) Amino acids (and thus proteins) also have nitrogen atoms; thus, the radioactivity would not distinguish between DNA and proteins.

E

70) If cells are grown in a medium containing radioactive 15N, which of these molecules will be labeled? A) fatty acids only B) nucleic acids only C) proteins only D) amylase only E) both proteins and nucleic acids

E

71) How will brief heating (to 95°C) affect macromolecular structures in aqueous solution? A) DNA duplexes will unwind and separate. B) Proteins will unfold (denature). C) Starch will hydrolyze into monomeric sugars. D) Proteins will hydrolyze into amino acids. E) DNA duplexes will unwind and separate, and proteins will unfold (denature).

E

74) Which of the following descriptors is true of the molecule shown in Figure 5.1? A) hexose B) fructose C) glucose D) hexose and fructose only E) hexose and glucose only

E

77) The molecule shown in Figure 5.3 is a A) polysaccharide. B) polypeptide. C) saturated fatty acid. D) triacylglycerol. E) unsaturated fatty acid.

E

86) Which of the following molecules contain(s) an aldehyde type of carbonyl functional group? A) 1 B) 4 C) 8 D) 10 E) 1 and 4

E

88) Which molecule is a saturated fatty acid? A) 1 B) 5 C) 6 D) 8 E) 9

E

89) Which of the following molecules is a purine type of nitrogenous base? A) 2 B) 3 C) 5 D) 12 E) 13

E

96) Which of the following molecules contains a glycosidic linkage type of covalent bond? A) 4 B) 6 C) 12 D) 13 E) 15

E

99) Which of the following statements is false? A) Molecules 1 and 4 could be joined together by a glycosidic linkage to form a disaccharide. B) Molecules 9 and 10 could be joined together by ester bonds to form a triacylglycerol. C) Molecules 2 and 7 could be joined together to form a short peptide. D) Molecules 2, 7, and 8 could be joined together to form a short peptide. E) Molecules 14 and 15 could be joined together to form a polypeptide.

E

Approximately what proportion of the DNA in the human genome codes for proteins or functional RNA?

E) 1.5%

15) Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed by the reactions of glycolysis?

E) 100%

91) For each molecule of glucose that is metabolized by glycolysis and the citric acid cycle (see Figure 9.2), what is the total number of NADH + FADH2 molecules produced?

E) 12

46) Approximately how many molecules of ATP are produced from the complete oxidation of two molecules of glucose (C6H12O6) in aerobic cellular respiration?

E) 60-64

29) In order to identify a specific restriction fragment using a probe, what must be done? A) The fragments must be separated by electrophoresis. B) The fragments must be treated with heat or chemicals to separate the strands of the double helix. C) The probe must be hybridized with the fragment. D) Only A and B are correct. E) A, B, and C are correct.

E) A, B, and C are correct.

Since Watson and Crick described DNA in 1953, which of the following might best explain why the function of small RNAs is still being explained?

E) Changes in technology as well as our ability to determine how much of the DNA is expressed have now made this possible.

34) During aerobic respiration, which of the following directly donates electrons to the electron transport chain at the lowest energy level?

E) FADH2

At what point in cell division is a chromosome lost so that, after fertilization with a normal gamete, the result is an embryo with 45, X?

E) I, II, III, or IV I. an error in anaphase I II. an error in anaphase II III. an error of the first postfertilization mitosis IV. an error in pairing

71) Phosphofructokinase is an important control enzyme in the regulation of cellular respiration. Which of the following statements correctly describes phosphofructokinase activity?

E) It is an allosteric enzyme.

Which of the following statements about the DNA in one of your brain cells is true?

E) It is the same as the DNA in one of your heart cells.

23) Why is glycolysis described as having an investment phase and a payoff phase?

E) It uses stored ATP and then forms a net increase in ATP.

80) If an enzyme is added to a solution where its substrate and product are in equilibrium, what will occur?

E) Nothing; the reaction will stay at equilibrium.

39) Which uses reverse transcriptase to make cDNA followed by amplification? A) Southern blotting B) Northern blotting C) Western blotting D) Eastern blotting E) RT-PCR

E) RT-PCR

24) When 10,000 molecules of ATP are hydrolyzed to ADP and i in a test tube, about twice as much heat is liberated as when a cell hydrolyzes the same amount of ATP. Which of the following is the best explanation for this observation?

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

What is the sugar component of ATP?

E) Ribose

59) Why would Gleevec most probably cause remission of the disease? A) It reverses the chromosomal translocation. B) It eliminates the Ph' chromosome. C) It removes Ph'-containing progenitor cells. D) The drug inhibits the replication of the affected chromosome. E) The drug inhibits the specific thymine kinase receptor.

E) The drug inhibits the specific thymine kinase receptor.

In comparing DNA replication with RNA transcription in the same cell, which of the following is true only of replication?

E) The entire template molecule is represented in the product.

If she moves the repressor gene (lac I), along with its promoter, to a position at some several thousand base pairs away from its normal position, which will you expect to occur?

E) The lac operon will function normally.

What is meant by the term "energy coupling"?

E) The use of an exergonic reaction to drive and endergonic one

30) What is the difference (if any) between the structure of ATP and the structure of the precursor of the A nucleotide in RNA?

E) There is no difference.

17) A researcher needs to clone a sequence of part of a eukaryotic genome in order to express the sequence and to modify the polypeptide product. She would be able to satisfy these requirements by using which of the following vectors? A) a bacterial plasmid B) BAC to accommodate the size of the sequence C) a modified bacteriophage D) a human chromosome E) a YAC with appropriate cellular enzymes

E) a YAC with appropriate cellular enzymes

Which of the following mutations would be most likely to have a harmful effect on an organism?

E) a single nucleotide insertion downstream of, and close to, the start of the coding sequence

The role of a metabolite that controls a repressible operon is to

E) bind to the repressor protein and activate it.

Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the

E) bonding of the anticodon to the codon and the attachment of amino acids to tRNAs.

In eukaryotes, transcription is generally associated with

E) both euchromatin and histone acetylation.

75) What is the purpose of beta oxidation in respiration?

E) breakdown of fatty acids

15) A system at chemical equilibrium

E) can do no work.

14) A molecule with the chemical formula C6H12O6 is probably a A) carbohydrate. B) lipid. C) monosaccharide D) carbohydrate and lipid only. E) carbohydrate and monosaccharide only.

E) carbohydrate and monosaccharide only.

1) Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?

E) catabolism

15) Yeast artificial chromosomes contain which of the following elements? A) centromere only B) telomeres only C) origin of replication only D) centromeres and telomeres only E) centromere, telomeres, and an origin of replication

E) centromere, telomeres, and an origin of replication

36) Inside an active mitochondrion, most electrons follow which pathway?

E) citric acid cycle → NADH → electron transport chain → oxygen

A lack of this nonprotein molecule would result in the inability of the cell to ʺturn offʺ genes:

E) corepressor

53) Genetic engineering is being used by the pharmaceutical industry. Which of the following is not currently one of the uses? A) production of human insulin B) production of human growth hormone C) production of tissue plasminogen activator D) genetic modification of plants to produce vaccines E) creation of products that will remove poisons from the human body

E) creation of products that will remove poisons from the human body

9) Where does glycolysis take place in eukaryotic cells?

E) cytosol

A frameshift mutation could result from

E) either an insertion or a deletion of a base.

2) Molecules with which functional groups may form polymers via dehydration reactions? A) hydroxyl groups B) carbonyl groups C) carboxyl groups D) either carbonyl or carboxyl groups E) either hydroxyl or carboxyl groups

E) either hydroxyl or carboxyl groups

55) Which catabolic processes may have been used by cells on ancient Earth before free oxygen became available?

E) glycolysis, pyruvate oxidation, the citric acid cycle, and oxidative phosphorylation, using an electron acceptor other than oxygen

Forms of the ras protein found in tumors usually cause which of the following?

E) growth factor signaling to be hyperactive

A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. One of her colleagues suggested she try increased methylation of C nucleotides in a mammalian system. Which of the following results would she most likely see?

E) inactivation of the selected genes

If glucose is available in the environment of E. coli, the cell responds with very low concentration of cAMP. When the cAMP increases in concentration, it binds to CAP. Which of the following would you expect would then be a measurable effect?

E) increased concentrations of sugars such as arabinose in the cell

The enzyme amylase can break glycolysidic linkages between glucose monomers only if the monomers are in a helix form which of the following Can amylase breakdown

Glycogen, starch, & and Amylopectin

63) An organism is discovered that thrives both in the presence and absence of oxygen in the air. Curiously, the consumption of sugar increases as oxygen is removed from the organism's environment, even though the organism does not gain much weight. This organism

E) is a facultative anaerobe.

26) During cellular respiration, acetyl CoA accumulates in which location?

E) mitochondrial matrix

43) Which of the following is most closely identical to the formation of twins? A) cell cloning B) therapeutic cloning C) use of adult stem cells D) embryo transfer E) organismal cloning

E) organismal cloning

45) Which of the following produces the most ATP when glucose (C6H12O6) is completely oxidized to carbon dioxide (CO2) and water?

E) oxidative phosphorylation (chemiosmosis)

Your brother has just purchased a new plastic model airplane. He places all the parts on the table in approximately the positions in which they will be located when the model is complete. His actions are analogous to which process in development?

E) pattern formation

105) What is the oxidizing agent in the following reaction?

E) pyruvate

25) Which of the following is used to make complementary DNA (cDNA) from RNA? A) restriction enzymes B) gene cloning C) DNA ligase D) gel electrophoresis E) reverse transcriptase

E) reverse transcriptase

35) What aspects of protein structure are stabilized or assisted by hydrogen bonds? A) primary structure B) secondary structure C) tertiary structure D) quaternary structure E) secondary, tertiary, and quaternary structures, but not primary structure

E) secondary, tertiary, and quaternary structures, but not primary structure

This is the site in the DNA located near the end of the final exon, encoding an RNA sequence that determines the 3ʹ end of the transcript:

E) terminator

8) Bacteria containing a plasmid into which the eukaryotic gene has integrated would grow in A) the nutrient broth only. B) the nutrient broth and the tetracycline broth only. C) the nutrient broth, the ampicillin broth, and the tetracycline broth. D) all four types of broth. E) the ampicillin broth and the nutrient broth.

E) the ampicillin broth and the nutrient broth.

Which of the following is the first event to take place in translation in eukaryotes?

E) the small subunit of the ribosome recognizes and attaches to the 5' cap of mRNA

12) Which of the following is the smallest closed system?

E) the universe

74) In vertebrate animals, brown fat tissue's color is due to abundant blood vessels and capillaries. White fat tissue, on the other hand, is specialized for fat storage and contains relatively few blood vessels or capillaries. Brown fat cells have a specialized protein that dissipates the proton-motive force across the mitochondrial membranes. Which of the following might be the function of the brown fat tissue?

E) to regulate temperature by converting most of the energy from NADH oxidation to heat

33) Dehydration reactions are used in forming which of the following compounds? A) triacylglycerides B) polysaccharides C) proteins D) triacylglycerides and proteins only E) triacylglycerides, polysaccharides, and proteins

E) triacylglycerides, polysaccharides, and proteins

The tryptophan operon is a repressible operon that is

E) turned off whenever tryptophan is added to the growth medium.

Which of the following can contribute to the development of cancer?

E)random spontaneous mutations , mutations caused by X-rays , transposition , chromosome translocations

Telophase l

Each half of the cell has a haploid set of chromosomes; still consists of 2 sister chromatids Cytokinesis usually occurs simultaneously, forming 2 haploid daughter cells

The alternative pathways of photosynthesis using the C4 or CAM systems are said to be compromises. Why?

Each one minimizes both water loss and rate of photosynthesis

Kinetic energy

Energy of motion

Chemical energy

Energy stored in chemical bonds (ATP)

Potential energy

Energy stored in matter due to position

Hydrangea plants of some 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?

Environmental factors such as soil pH.

True or False: Antibiotics are effective against viruses.

False.

True or False: Viral infections never go away without treatment.

False.

The most biologically important Lipids

Fats, Phospholipids, and Steroids.

Disaccharides

Formed when a dehydration reaction joins two monosaccharides.

Hormonal Proteins

Function: Coordination of an organism's activities (Insulin)

Contractile and motor proteins

Function: Movement

Defensive Proteins

Function: Protect against disease (Antibodies)

Receptor Proteins

Function: Response of cell to chemical stimuli

Storage Proteins

Function: Storage of amino acids

Structural Proteins

Function: Support

Transport Proteins

Function: Transport of substances

The greatest distance among the three genes is between a and c. What does this mean?

Gene a is between b and c

Gametes (Sperm & eggs)

Genes are passed to the next generation via reproductive cells called

Carotenoids are often found in foods that are considered to have antioxidant properties in human nutrition. What related function do they have in plants?

They dissipate excessive light energy

Which of the following statements concerning unsaturated fats is true

They have double bonds in the carbon chains of their fatty acids

Why are C4 plants able to photosynthesize with no apparent photorespiration?

They use PEP carboxylase to initially fix CO2

Energy Storage

This is the main function of fats

DNA

This provides direction for its own replication.

Why did Mendel continue some of his experiments to the F2 or F3 generation?

To observe whether or not a recessive trait would reappear.

What was the most significant conclusion that Mendel drew from his experiments with pea plants?

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

Mendel accounted for the observation that traits which had disappeared in the F1 generation reappeared in the F2 generation by proposing that...

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

True or False: Both viruses and bacteria can cause infection.

True.

True or False: Many bacteria don't cause infection.

True.

Poypeptides

Unbranched polymers built from the same set of 20 amino acids.

Genes

Units of heredity, and are made up of segments of DNA

Duchenne muscular dystrophy (DMD) is caused by 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?

Very rarely would a woman have this condition; the condition would be due to a chromosome error

Viruses

Viruses are 20x smaller than bacteria; made up of DNA or RNA; made of proteins (non-cellular); reproduce only thru host cell

B) a lipid made with three fatty acids and glyerol

What is a triacylglycerol? A) a protein with tertiary structure B) a lipid made with three fatty acids and glyerol C) a lipid that makes up much of the plasma membrane D) a molecule formed from three alcohols by dehydration reactions E) a carbohydrate with three sugars joined together by glycosidic linkages

C) dehydration reactions

What is the chemical mechanism by which cells make polymers from monomers? A) phosphodiester linkages B) hydrolysis C) dehydration reactions D) ionic bonding of monomers E) the formation of disulfide bridges between monomers

Hydrolysis

When polymers are dissassembled to monomers reversing the dehydration reaction

Dehydration Reaction

When two monomers bond together through the loss of a water molecule

C) a nitrogenous base, a phosphate group, and a pentose sugar

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 pentose sugar C) a nitrogenous base, a phosphate group, and a pentose sugar D) a phosphate group and an adenine or uracil E) a pentose sugar and a purine or pyrimidine

B) lipids

Which of the following is a diverse group of hydrophobic molecules? A) carbohydrates B) lipids C) proteins D) nucleic acids

A) glucose

Which of the following is not a polymer? A) glucose B) starch C) cellulose D) chitin E) DNA

Correct Answer: A) They are both polymers of glucose. Incorrect Answers: (C) Neither starch nor cellulose can be digested by humans (D) Only starch is used for energy storage in plants (E) Only cellulose is a structural component of the plant cell wall (B) They are not geometric isomers of each other.

Which of the following is true of both starch and cellulose? A) They are both polymers of glucose. B) They are geometric isomers of each other. C) They can both be digested by humans. D) They are both used for energy storage in plants. E) They are both structural components of the plant cell wall.

Correct Answer D) It is a major structural component of plant cell walls. Incorrect answers: (B) Starch is the storage polysaccharide for energy in plant cells (not cellulose) (C) Glycogen is the storage polysaccharide for energy in animal cells (E) Phospholipids are a major structural component of animal cell plasma membranes (A) Cellulose is made of long polymer chains of glucose units. Sucrose is a disaccharide that makes up table sugar.

Which of the following is true of cellulose? A) It is a polymer composed of sucrose monomers. B) It is a storage polysaccharide for energy in plant cells. C) It is a storage polysaccharide for energy in animal cells. D) It is a major structural component of plant cell walls. E) It is a major structural component of animal cell plasma membranes.

C) They are the principal molecules in lard and butter.

Which of the following is true regarding saturated fatty acids? A) They are the predominant fatty acid in corn oil. B) They have double bonds between carbon atoms of the fatty acids. C) They are the principal molecules in lard and butter. D) They are usually liquid at room temperature. E) They are usually produced by plants.

D) chitin

Which of the following polymers contain nitrogen? A) starch B) glycogen C) cellulose D) chitin E) amylopectin

C) DNA nucleotides contain a different sugar than RNA nucleotides. A) is incorrect because RNA is not a protein. Both RNA and DNA are nucleic acids B) is incorrect because both RNA and DNA are nucleic acids D) is incorrect because the correct answer is opposite. DNA is a double helix, RNA is single stranded. E) is incorrect because both A and D are incorrect!

Which of the following statements best summarizes the structural differences between DNA and RNA? A) RNA is a protein, whereas DNA is a nucleic acid. B) DNA is a protein, whereas RNA is a nucleic acid. C) DNA nucleotides contain a different sugar than RNA nucleotides. D) RNA is a double helix, but DNA is single-stranded. E) A and D are correct.

A) They are soluble in water. Lipids are hydrophobic so NOT soluble in water. The rest are true of lipids, they are important constituents of cell membranes, contain more energy than proteins and carbohydrates and they are not true polymers and waxes steroids do contain lipids

Which of the following statements is false for the class of biological molecules known as lipids? A) They are soluble in water. B) They are an important constituent of cell membranes. C) They contain more energy than proteins and carbohydrates. D) They are not true polymers. E) They contain waxes and steroids.

C) Molecules of this type are usually liquid at room temperature. This is an unsaturated fatty acid because of its double carbon bonds. Unsaturated fatty acids are healthier, do not lead to cardiac disease (atherosclerosis) and are liquid at room temperature (think olive oil, vegetable oil etc)

Which of the following statements is true regarding the molecule illustrated in Figure 5.3? A) It is a saturated fatty acid. B) A diet rich in this molecule may contribute to atherosclerosis. C) Molecules of this type are usually liquid at room temperature. D) A and B only E) A, B and C

The sex chromosomes which determine the sex of the individual are called

X and Y chromosomes

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?

XCXc and XCY

According to the fluid mosaic model of cell membranes, which of the following is a true statement about membrane phospholipids? A) They can move laterally along the plane of the membrane. B) They frequently flip-flop from one side of the membrane to the other. C) They occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane. D) They are free to depart from the membrane and dissolve in the surrounding solution. E) They have hydrophilic tails in the interior of the membrane.

a

Familial hypercholesterolemia is characterized by which of the following? 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 E) a general lack of glycolipids in the blood cell membranes

a

In most cells, there are electrochemical gradients of many ions across the plasma membrane even though there are usually only one or two electrogenic pumps present in the membrane. The gradients of the other ions are most likely accounted for by A) cotransport proteins. B) ion channels. C) carrier proteins. D) B and C only E) A, B, and C

a

The difference between pinocytosis and receptor-mediated endocytosis is that A) pinocytosis brings only water 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 requires cellular energy, but receptor-mediated endocytosis does not. E) pinocytosis can concentrate substances from the extracellular fluid, but receptor-mediated endocytosis cannot.

a

The presence of cholesterol in the plasma membranes of some animals A) enables the membrane to stay fluid more easily when cell temperature drops. B) enables the animal to remove hydrogen atoms from saturated phospholipids. C) enables the animal to add hydrogen atoms to unsaturated phospholipids. D) makes the membrane less flexible, allowing it to sustain greater pressure from within the cell. E) makes the animal more susceptible to circulatory disorders.

a

The sodium-potassium pump in animal cells requires cytoplasmic ATP to pump ions across the plasma membrane. When the proteins of the pump are first synthesized in the rough ER, what side of the ER membrane will the ATP binding site be on? A) It will be on the cytoplasmic side of the ER. B) It will be on the side facing the interior of the ER. C) It could be facing in either direction because the orientation of proteins is scrambled in the Golgi apparatus. D) It doesnʹt matter, because the pump is not active in the ER.

a

Which line represents the bag with the highest initial concentration of sucrose?

a

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 E) a greater proportion of relatively large glycolipids compared with lipids having smaller molecular masses

a

Which of the following is a reasonable explanation for why unsaturated fatty acids help keep any membrane more fluid at lower temperatures? A) The double bonds form kinks in the fatty acid tails, forcing adjacent lipids to be further apart. B) Unsaturated fatty acids have a higher cholesterol content and therefore more cholesterol in membranes. C) Unsaturated fatty acids permit more water in the interior of the membrane. D) The double bonds block interaction among the hydrophilic head groups of the lipids. E) The double bonds result in shorter fatty acid tails and thinner membranes.

a

Which of the following is one of the ways that the membranes of winter wheat are able to remain fluid when it is extremely cold? A) by increasing the percentage of unsaturated phospholipids in the membrane B) by increasing the percentage of cholesterol molecules in the membrane C) by decreasing the number of hydrophobic proteins in the membrane D) by co-transport of glucose and hydrogen E) by using active transport

a

Which of the following span the phospholipids bilayer, usually a number of times? A) transmembrane proteins B) integral proteins C) peripheral proteins D) integrins E) glycoproteins

a

Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly? A) CO2 B) an amino acid C) glucose D) K+ E) starch

a

Who proposed that membranes are a phospholipid bilayer between two layers of hydrophilic proteins? A) H. Davson and J. Danielli B) I. Langmuir C) C. Overton D) S. Singer and G. Nicolson E) E. Gorter and F. Grendel

a

SRY is best described in which of the following ways?

a gene region present on the Y chromosome that triggers male development

A gene is considered to be non-Mendelian in its inheritance pattern if it seems to "violate" Mendel's laws. Which of the following would be considered Mendelian?

a gene transmitted to males from the maternal line and from fathers to daughters

fibronectin

a glycoprotein that helps cells attach to extracellular matrix

What is a syndrome?

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

Which of the following is known as a Philadelphia chromosome?

a human chromosome 22 that has had a specific translocation

Calico cats are female because

a male inherits only one of the two X-linked genes controlling hair color

Locus

a specific location of a gene on a certain chromosome

Which of the following produces a Mendelian pattern of inheritance?

a trait acted upon by many genes

In humans, clear gender differentiation occurs, not at fertilization, but after the second month of gestation. What is the first event of this differentiation?

activation of SRY in male embryos and masculinization of the gonads

In autotrophic bacteria, where are the enzymes located that can carry on organic synthesis?

along the inner surface of the plasma membrane

peroxisomes

animal orgnalles that contain enzymes that detoxify alcohols, hydrogen peroxide, and other harmful chemicals

cytosol

aqueous part of cytoplasm within which particles and organelles are suspended

Gametes

are only types of human cells produced by meiosis, rather than mitosis

In any ecosystem, terrestrial or aquatic, what group(s) is (are) always necessary?

autotrophs

Which of the following statements is a correct distinction between autotrophs and heterotrophs?

autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic

An animal cell lacking oligosaccharides 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) maintaining fluidity of the phospholipid bilayer D) attaching to the cytoskeleton E) establishing the diffusion barrier to charged molecules

b

At the beginning of the experiment, 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 hypertonic to side B with respect to glucose. E) side A is hypotonic to side B with respect to sodium chloride.

b

Based on Figure 7.19 in your textbook, which of these experimental treatments would increase the rate of sucrose transport into the cell? A) decreasing extracellular sucrose concentration B) decreasing extracellular pH C) decreasing cytoplasmic pH D) adding an inhibitor that blocks the regeneration of ATP E) adding a substance that makes the membrane more permeable to hydrogen ions

b

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. E) Some membranes have hydrophobic surfaces exposed to the cytoplasm, while others have hydrophilic surfaces facing the cytoplasm.

b

In which of the following would there be the greatest need for osmoregulation? A) an animal connective tissue cell bathed in isotonic body fluid B) a terrestrial animal such as a snake C) a red blood cell surrounded by plasma D) a lymphocyte before it has been taken back into lymph fluid E) a plant being grown hydroponically (in a watery mixture of designated nutrients)

b

The formulation of a model for a structure or for a process serves which of the following purposes? A) It asks a scientific question. B) It functions as a testable hypothesis. C) It records observations. D) It serves as a data point among results. E) It can only be arrived at after years of experimentation.

b

What kinds of molecules pass through a cell membrane most easily? A) large and hydrophobic B) small and hydrophobic C) large polar D) ionic E) monosaccharides such as glucose

b

Which line or lines represent(s) bags that contain a solution that is hypertonic at the end of 60 minutes? A) A and B B) B C) C D) D E) D and E

b

Which of the following is a characteristic feature of a carrier protein in a plasma membrane? A) It is a peripheral membrane protein. B) It exhibits a specificity for a particular type of molecule. C) It requires the expenditure of cellular energy to function. D) It works against diffusion. E) It has few, if any, hydrophobic amino acids.

b

Which of the following would you expect to be a problem for someone with nonfunctional chloride channeling? A) inadequate secretion of mucus B) buildup of excessive secretions in organs such as lungs C) buildup of excessive secretions in glands such as the pancreas D) sweat that includes no NaCl E) mental retardation due to low salt levels in brain tissue

b

White blood cells engulf bacteria through what process? A) exocytosis B) phagocytosis C) pinocytosis D) osmosis E) receptor-mediated exocytosis

b

Which of the following two genes are closest on a genetic map of Drosophila?

b and rb

In a series of mapping experiments, the recombination frequencies for four different linked genes of Drosophila were determined as shown in Figure 15.2. What is the order of these genes on a chromosome map?

b-rb-cn-vg

A plant has a unique photosynthetic pigment. The leaves of this plant appear to be reddish yellow. What wavelengths of visible light are being absorbed by this pigment?

blue and violet

In metabolic processes of cell respiration and photosynthesis, prosthetic groups such as heme and iron-sulfur complexes are encountered. What do they do?

both oxidize and reduce during electron transport

A patient has had a serious accident and lost a lot of blood. In an attempt to replenish body fluids, distilled water, equal to the volume of blood lost, is transferred directly into one of his veins. What will be the most probable result of this transfusion? A) It will have no unfavorable effect as long as the water is free of viruses and bacteria. B) The patientʹs red blood cells will shrivel up because the blood fluid is hypotonic compared to the cells. C) The patientʹs red blood cells will swell because the blood fluid is hypotonic compared to the cells. D) The patientʹs red blood cells will shrivel up because the blood fluid is hypertonic compared to the cells. E) The patientʹs red blood cells will burst because the blood fluid is hypertonic compared to the cells.

c

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 core of the membrane. C) embedded in a lipid bilayer. D) randomly oriented in the membrane, with no fixed inside-outside polarity. E) free to depart from the fluid membrane and dissolve in the surrounding solution.

c

After the system reaches equilibrium, what changes are observed? A) The molarity of sucrose and glucose are equal on both sides. B) The molarity of glucose is higher in side A than in side B. C) The water level is higher in side A than in side B. D) The water level is unchanged. E) The water level is higher in side B than in side A.

c

Celery stalks that are immersed in fresh water for several hours become stiff and hard. Similar stalks left in a salt solution become limp and soft. From this we can deduce that the cells of the celery stalks are A) hypotonic to both fresh water and the salt solution. B) hypertonic to both fresh water and the salt solution. C) hypertonic to fresh water but hypotonic to the salt solution. D) hypotonic to fresh water but hypertonic to the salt solution. E) isotonic with fresh water but hypotonic to the salt solution.

c

Cell membranes are asymmetrical. Which of the following is a most likely explanation? A) The cell membrane forms a border between one cell and another in tightly packed tissues such as epithelium. B) Cell membranes communicate signals from one organism to another. C) Cell membrane proteins are determined as the membrane is being packaged in the ER and Golgi. D) The ʺinnernessʺ and ʺouternessʺ of membrane surfaces are predetermined by genes. E) Proteins can only span cell membranes if they are hydrophobic.

c

Chloride ion channels are membrane structures that include which of the following? A) gap junctions B) aquaporins C) hydrophilic proteins D) carbohydrates E) sodium ions

c

In order for a protein to be an integral membrane protein it would have to be which of the following? A) hydrophilic B) hydrophobic C) amphipathic D) completely covered with phospholipids E) exposed on only one surface of the membrane

c

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 E) on the ER

c

Initially, in terms of tonicity, the solution in side A with respect to that in side B is A) hypotonic. B) plasmolyzed. C) isotonic. D) saturated. E) hypertonic.

c

The movement of potassium into an animal cell requires A) low cellular concentrations of sodium. B) high cellular concentrations of potassium. C) an energy source such as ATP or a proton gradient. D) a cotransport protein. E) a gradient of protons across the plasma membrane.

c

The sodium-potassium pump is called an electrogenic pump because it A) pumps equal quantities of Na+ and K+ across the membrane. B) pumps hydrogen ions out of the cell. C) contributes to the membrane potential. D) ionizes sodium and potassium atoms. E) is used to drive the transport of other molecules against a concentration gradient.

c

What is the voltage across a membrane called? A) water potential B) chemical gradient C) membrane potential D) osmotic potential E) electrochemical gradient

c

Which line represents the bag that contained a solution isotonic to the 0.6 molar solution at the beginning of the experiment?

c

Which of the following is true of integral membrane proteins? A) They lack tertiary structure. B) They are loosely bound to the surface of the bilayer. C) They are usually transmembrane proteins. D) They are not mobile within the bilayer. E) They serve only a structural role in membranes.

c

Which of the following membrane activities require energy from ATP hydrolysis? A) facilitated diffusion. B) movement of water into a cell C) Na+ ions moving out of the cell D) movement of glucose molecules E) movement of water into a paramecium

c

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

c

Which of the following types of molecules are the major structural components of the cell membrane? A) phospholipids and cellulose B) nucleic acids and proteins C) phospholipids and proteins D) proteins and cellulose E) glycoproteins and cholesterol

c

Which of these are not embedded in the lipid bilayer at all? A) transmembrane proteins B) integral proteins C) peripheral proteins D) integrins E) glycoproteins

c

Why are lipids and proteins free to move laterally in membranes? A) The interior of the membrane is filled with liquid water. B) There are no covalent bonds between lipid and protein 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. E) Molecules such as cellulose can pull them in various directions.

c

eukaryote

cells with nucleus and membrane bound organelles

Correns described that the inheritance of variegated color on the leaves of certain plants was determined by the maternal parent only. What phenomenon does this describe?

chloroplast inheritance

cytoplasmic streaming

circular flow of cytosol using myosin and actin filaments that speeds up distribution of materials within cells

chromosome

condensed chromatin (used during cell division)

As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in 1 hour. You find 30,000 molecules of ATP consumed, but only 20,000 molecules of NADPH. Where did the extra ATP molecules come from?

cyclic electron flow

9+2 structure

cylinder of 9 microtubule doublets around a 1 doublet (make up cilia, flagella, mitotic spindle)

After a membrane freezes and then thaws, it often becomes leaky to solutes. The most reasonable explanation for this is that A) transport proteins become nonfunctional during freezing. B) the lipid bilayer loses its fluidity when it freezes. C) aquaporins can no longer function after freezing. D) the integrity of the lipid bilayer is broken when the membrane freezes. E) the solubility of most solutes in the cytoplasm decreases on freezing.

d

An organism with a cell wall would have the most difficulty doing which process? A) diffusion B) osmosis C) active transport D) phagocytosis E) facilitated diffusion

d

If a young male child has cystic fibrosis, which of the following would affect his fertility? A) inability to make sperm B) incomplete maturation of the testes C) failure to form genital structures appropriately D) incorrect concentrations of ions in semen E) abnormal pH in seminal fluid

d

If you examine side A after 3 days, you should find A) a decrease in the concentration of NaCl and glucose and an increase in the water level. B) a decrease in the concentration of NaCl, an increase in water level, and no change in the concentration of glucose. C) no net change in the system. D) a decrease in the concentration of NaCl and a decrease in the water level. E) no change in the concentration of NaCl and glucose and an increase in the water level.

d

In the years since the proposal of the fluid mosaic model of the cell membrane, which of the following observations has been added to the model? A) The membrane is only fluid across a very narrow temperature range. B) Proteins rarely move, even though they possibly can do so. C) Unsaturated lipids are excluded from the membranes. D) The concentration of protein molecules is now known to be much higher. E) The proteins are known to be made of only acidic amino acids.

d

Ions diffuse across membranes down their A) chemical gradients. B) concentration gradients. C) electrical gradients. D) electrochemical gradients. E) A and B are correct.

d

Proton pumps are used in various ways by members of every kingdom of organisms. What does this most probably mean? A) Proton pumps must have evolved before any living organisms were present on the earth. B) Proton pumps are fundamental to all cell types. C) The high concentration of protons in the ancient atmosphere must have necessitated a pump mechanism. D) Cells with proton pumps were maintained in each Kingdom by natural selection. E) Proton pumps are necessary to all cell membranes.

d

When a membrane is freeze-fractured, the bilayer splits down the middle between the two layers of phospholipids. In an electron micrograph of a freeze-fractured membrane, the bumps seen on the fractured surface of the membrane are A) peripheral proteins. B) phospholipids. C) carbohydrates. D) integral proteins. E) cholesterol molecules.

d

Which of the following is true of the evolution of cell membranes? A) Cell membranes have stopped evolving now that they are fluid mosaics. B) Cell membranes cannot evolve if proteins do not. C) The evolution of cell membranes is driven by the evolution of glycoproteins and glycolipids. D) As populations of organisms evolve, different properties of their cell membranes are selected for or against. E) An individual organism selects its preferred type of cell membrane for particular functions.

d

Which of the following processes includes all others? A) osmosis B) diffusion of a solute across a membrane C) facilitated diffusion D) passive transport E) transport of an ion down its electrochemical gradient

d

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

d

Which of these are attached to the extracellular matrix? A) transmembrane proteins B) integral proteins C) peripheral proteins D) integrins E) glycoproteins

d

Who proposed that the membrane is a mosaic of protein molecules bobbing in a fluid bilayer of phospholipids? A) H. Davson and J. Danielli B) I. Langmuir C) C. Overton D) S. Singer and G. Nicolson E) E. Gorter and F. Grendel

d

You are working on a team that is designing a new drug. In order for this drug to work, it must enter the cytoplasm of specific target cells. Which of the following would be a factor that determines whether the molecule enters the cell? A) blood or tissue type of the patient B) non-polarity of the drug molecule C) lack of charge on the drug molecule D) similarity of the drug molecule to other molecules transported by the target cells E) lipid composition of the target cellsʹ plasma membrane

d

A nonreciprocal crossover causes which of the following products?

deletion and duplication

nucleoid

densly staining DNA region in a prokaryotic cell

A cell whose cytoplasm has a concentration of 0.02 molar glucose is placed in a test tube of water containing 0.02 molar glucose. Assuming that glucose is not actively transported into the cell, which of the following terms describes the tonicity of the external solution relative to the cytoplasm of the cell? A) turgid B) hypertonic C) hypotonic D) flaccid E) isotonic

e

Glucose diffuses slowly through artificial phospholipid bilayers. The cells lining the small intestine, however, rapidly move large quantities of glucose from the glucose-rich food into their glucose-poor cytoplasm. Using this information, which transport mechanism is most probably functioning in the intestinal cells? A) simple diffusion B) phagocytosis C) active transport pumps D) exocytosis E) facilitated diffusion

e

If a membrane protein in an animal cell is involved in the cotransport of glucose and sodium ions into the cell, which of the following is most likely true? A) The sodium ions are moving down their electrochemical gradient while glucose is moving up. B) Glucose is entering the cell along its concentration gradient. C) Sodium ions can move down their electrochemical gradient through the cotransporter whether or not glucose is present outside the cell. D) Potassium ions move across the same gradient as sodium ions. E) A substance that blocked sodium ions from binding to the cotransport protein would also block the transport of glucose.

e

Of the following functions, which is most important for the glycoproteins and glycolipids of animal cell membranes? A) facilitated diffusion of molecules down their concentration gradients B) active transport of molecules against their concentration gradients C) maintaining the integrity of a fluid mosaic membrane D) maintaining membrane fluidity at low temperatures E) a cellʹs ability to distinguish one type of neighboring cell from another

e

Several seriously epidemic viral diseases of earlier centuries were then incurable 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? A) antiviral medications that are efficient and work well with all viruses B) antibiotics against the viruses in question C) intravenous feeding techniques D) medication to prevent blood loss E) hydrating drinks that include high concentrations of salts and glucose

e

Water passes quickly through cell membranes because A) the bilayer is hydrophilic. B) it moves through hydrophobic channels. C) water movement is tied to ATP hydrolysis. D) it is a small, polar, charged molecule. E) it moves through aquaporins in the membrane.

e

What are the membrane structures that function in active transport? A) peripheral proteins B) carbohydrates C) cholesterol D) cytoskeleton filaments E) integral proteins

e

What mechanisms do plants use to load sucrose produced by photosynthesis into specialized cells in the veins of leaves? A) an electrogenic pump B) a proton pump C) a contransport protein D) A and C only E) A, B, and C

e

When a plant cell, such as one from a peony stem, is submerged in a very hypotonic solution, what is likely to occur? A) the cell will burst B) the cell membrane will lyse C) plasmolysis will shrink the interior D) the cell will become flaccid E) the cell will become turgid

e

When biological membranes are frozen and then fractured, they tend to break along the middle of the bilayer. The best explanation for this is that A) the integral membrane proteins are not strong enough to hold the bilayer together. B) water that is present in the middle of the bilayer freezes and is easily fractured. C) hydrophilic interactions between the opposite membrane surfaces are destroyed on freezing. D) the carbon-carbon bonds of the phospholipid tails are easily broken. E) the hydrophobic interactions that hold the membrane together are weakest at this point.

e

Which of these often serve as receptors or cell recognition molecules on cell surfaces? A) transmembrane proteins B) integral proteins C) peripheral proteins D) integrins E) glycoproteins

e

Who was/were the first to propose that cell membranes are phospholipid bilayers? A) H. Davson and J. Danielli B) I. Langmuir C) C. Overton D) S. Singer and G. Nicolson E) E. Gorter and F. Grendel

e

What does the chemiosmotic process in chloroplasts involve?

establishment of a proton gradient

collagen

fibrous protein found in connective tissues and ECM

microvilli

finger-like extensions of cells that increase surface area to increase absorption (ex. small intestine)

CAM plants keep stomata closed in daytime, thus reducing loss of water. They can do this because they

fix CO2 into organic acids during the night

The two cell divisions result in

four daughter cells rather than the 2 daughter cells in mitosis

6) Which of the following is not a polymer? A) glucose B) starch C) cellulose D) chitin E) DNA

glucose

58) Which metabolic pathway is common to both cellular respiration and fermentation?

glycolysis

tetrad is a

group of four chromatids

Each daughter cell has _____ as many chromosomes as the parent cell

half

What proportion of their sons would be color-blind and of normal height?

half

In the thylakoid membranes, what is the main role of the antenna pigment molecules?

harvest photons and transfer light energy to the reaction-center chlorophyll

Human females have what specific chromosomes

homologous pair of X chromosomes (XX)

Example of Order

human genetic makeup, or the structure of DNA

scanning electron microscopy (SEM)

image of 3D surface coated with heavy metal like gold (100,000 X)

transmission electron microscopy (TEM)

image of ultra thin slice to view intracellular components (500,000 x)

How is photosynthesis similar in C4 and CAM plants?

in both cases, rubisco is not used to fix carbon initially

synapsis

in prophase I, replicated homologs pair up and become physically connected along their lengths by a zipper-like protein structure, the synaptonemal complex,

Example of Regulation or Homeostasis

insulin and blood glucose level maintenance (negative feedback mechanism)

Which of the following statements best describes the relationship between photosynthesis and respiration?

photosynthesis stores energy in complex organic molecules, while respiration releases it

Example of Response to Environment

phototropism (stimulus: light, tropism: orientation towards light). also: Venus flytrap closing on a fly (stimulus: touch; response: activating feeding mechanism, or closing)

plastids

plant organelles surrounded by double membrane with their own DNA, that make and store food and pigments

keratin

protein found in epidermis, hair, and nails

dyneins

proteins that connect microtubules in the 9+2 structure AND attach organelles to microtubules; when they contract, flagella/cilia move AND organelles "walk"

Which of the following are directly associated with photosystem I?

receiving electrons from plastocyanin

In the process of carbon fixation, RuBP attaches a CO2 to produce a 6 carbon molecule, which is then split in two. After phosphorylation and reduction, what more needs to happen in the Calvin cycle?

regeneration of rubisco

Which of the following does not occur during the Calvin cycle?

release of oxygen

Which process is most directly driven by light energy?

removal of electrons from chlorophyll molecules

Reduction of oxygen which forms water occurs during

respiration

contractile vacuole

saclike organelles that expand to collect excess water and contract to squeeze it out of cell

peptido/proteo-glycans

small core proteins with EXTENSIVE carbohydrate chains found in bacterial cell walls and animal ECM

vesicles

small sacs surrounded by phospholipid bilayer that specialize in moving products into, out of, and within a cell

What does the zygote produce

somatic cells by mitosis and develops into an adult

Prophase ll

spindle apparatus forms chromosomes move toward the metaphase plate

When oxygen is released as a result of photosynthesis, it is a by-product of which of the following?

splitting the water molecules

golgi apparatus

stack of membranes that modifies, sorts, and packages proteins for transport

basal body

star of 9 microtubules triplets that anchors cilia and flagella in membrane (resembles centrioles)

Where do the enzymatic reactions of the Calvin cycle take place?

stroma of the chloroplast

Where does the Calvin cycle take place?

stroma of the chloroplast

cell wall

strong supporting layer of cellulose, chitin, or peptidoglycans around cell membrane in plants, fungi, or bacteria

extracellular matrix (ECM)

substance in which animal cells are embedded, consisting of proteins and polysaccharides

What is the primary function of the Calvin cycle?

synthesize simple sugars from carbon dioxide

cell fractionation

technique that breaks cells and separates their components

psuedopodia

temporary projections of eukaryotic cell membranes or unicellular protists in direction of movement

metaphase l

tetrads line up at metaphase plate microtubules from one pole are attached to the kinetochore of one chromosome of each tetrad

Produces three-carbon sugars

the Calvin cycle alone

Requires ATP

the Calvin cycle alone

Requires CO2

the Calvin cycle alone

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. If you ran the same experiment without passing light through a prism, what would you predict?

the bacteria would be relatively evenly distributed along the algal filaments

Energy

the capacity to do work

Example of Growth and Development

the cycle of a blowfly (application: forensic science)

Variation is demonstrated by

the differences in appearance that offspring show from parents and siblings

Which statement describes the functioning of photosystem II?

the electron vacancies in P680 are filled by electrons derived from water

The sugar that results from the three "turns" of the Calvin cycle is glyceraldehyde-3-phosphate (G3P). Which of the following is a consequence of this?

the formation of starch in plants involves assembling many G3P molecules, with or without further rearrangements

Suppose the interior of the thylakoids of isolated chloroplasts were made acidic and then transferred in the dark to a pH-8 solution. What would be likely to happen?

the isolated chloroplasts will make ATP

In a protein complex for the light reaction (a reaction center), energy is transferred from pigment molecule to pigment molecule, to a special chlorophyll a molecule, and eventually to the primary electron acceptor. Why does this occur?

the molecular environment lets it boost an electron to higher energy level and also to transfer the electron to another molecule

Mitochondrial DNA is primarily involved in coding for proteins needed for electron transport. Therefore, in which body systems would you expect most mitochondrial gene mutations to be exhibited?

the nervous and muscular systems

The pH of the inner thylakoid space has been measured, as have the pH of the stroma and of the cytosol of a particular plant cell. Which, if any, relationship would you expect to find?

the pH within the thylakoid is less than that of the stroma

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. An outcome of this experiment was to help determine

the relationship between wavelengths of light and the oxygen released during photosynthesis

Like mitosis, meiosis is preceded by

the replication of chromosomes

In mitochondria, chemiosmosis translocated protons from the matrix into the intermembrane space, whereas in chloroplasts, chemiosmosis translocates protons from

the stroma to the thylakoid space

Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma. This damage will have the most direct effect on which of the following processes?

the synthesis of ATP

Living organisms are distinguished by

their ability to reproduce their own kind

What is the relationship between wavelength of light and the quantity of energy per photon?

they are inversely related

P680+ is said to be the strongest biological oxidizing agent. Why?

this molecule results from the transfer of an electron to the primary electron acceptor of photosystem II and strongly attracts another electron

The reaction-center chlorophyll of photosystem I is known as P700 because

this pigment is best at absorbing light with a wavelength of 700nm

In a plant cell, where are the ATP synthase complexes located?

thylakoid membrane and the inner mitochondrial membrane

Where are the molecules of the electron transport chain found in plant cells?

thylakoid membranes of chloroplasts

Some photosynthetic organisms contain chloroplasts that lack photosystem II, yet are able to survive. The best way to detect the lack of photosystem II in these organisms would be

to test for liberation of O2 in the light

In cats, black fur color is caused by an X-linked allele; the other allele at this locus causes orange color. The heterozygote is tortoiseshell. What kinds of offspring would you expect from the cross of a black female and an orange male?

tortoiseshell females; black males

One possible result of chromosomal breakage is for a fragment to join a nonhomologous chromosome. What is this alteration called?

translocation

Sex determination in mammals is due to the SRY region of the Y chromosome. An abnormality of this region could allow which of the following to have a male phenotype?

translocation of SRY to an autosome of a 46, XX individual

integrins

transmembrane proteins that connect both to outside extracellular matrix and inside cytoskeleton of animal cells.

glycoproteins

transmembrane proteins with SHORT carbohydrate chains that identify the cell

Phospholipids

two fatty acids and a phosphate group are attached to glycerol

chromatin

uncondensed DNA wrapped around histones (used during transcription)

prokaryote

unicellular organism without nucleus and membrane bound organelles (archea and bacteria)

Cyclic electron flow may be photoprotective (protective to light-induced damage). Which of the following experiments could provide information on this phenomenon?

using mutated organisms that can grow but that cannot carry out cyclic flow of electrons and compare their abilities to photosynthesize in different light intensities

phagocytosis

when extensions of cytoplasm surround and engulf LARGE food particles

Phospholipid Bilayer

when phospholipids are added to water

The fertilized egg is called a _____ and has _____ set of chromosomes from each parent

zygote, one