Bio Test 3

A

Cancer cells are different from other cells in that they have lost their "contact inhibition." "Contact inhibition" means that A) most cells stop dividing when they bump up against other cells or collections of cells. B) DNA replication in most cells stops when the double helix comes in contact with particular enzymes. C) DNA replication in most cells doesn't begin until the double helix comes in contact with particular enzymes. D) most cells stop dividing when they have reached 50 cell divisions. E) most cells don't begin to divide until they bump up against other cells or collections of cells.

E

Cellular respiration is the process by which A) ATP molecules are converted into water and sugar. B) light energy is converted into kinetic energy. C) oxygen is produced during metabolic activity. D) oxygen is used to transport chemical energy throughout the body. E) energy from the chemical bonds of food molecules is captured by an organism

C

Chemotherapy is one common treatment for cancer. Which of the following are aspects of chemotherapy? A) Drugs that interfere with cell division are administered to the patient. B) Chemotherapy drugs circulate throughout the entire body. C) All of the above answer choices are correct. D) Only the first and third answer choices are correct. E) Chemotherapy drugs disrupt normal systems that rely on the rapid and constant production of new cells.

B

Chlorophyll's most important role during photosynthesis is A) keeping the leaves of plants green. B) converting light energy from the Sun into chemical energy. C) capturing electrons that can, in turn, be used by carotenoids. D) turning into a molecule of ATP upon being struck by sunlight.

B

Chromosomes on which recombination takes place A) are created during meiosis. B) Both the first and second answer choices are correct. C) lead to the condition known as Down syndrome. D) have a mixtures of maternal and paternal chromosomes. E) usually result in aborted fetuses.

C

DNA replication occurs during the _____________ phase of the cell cycle. A) Gap 1 B) prophase C) S (DNA synthesis) D) Gap 2 E) M

D

Down syndrome results from which of the following chromosomal abnormalities? A) the absence of a second copy of chromosome 10 B) inversion of the long arm of chromosome 8 C) two Y chromosomes D) all or part of a third copy of chromosome 21 E) a truncated copy of chromosome 3

D

During C4 photosynthesis, plants A) are able to produce sugars without any input of carbon dioxide. B) utilize less ATP when producing sugar. C) are able to generate water molecules to cool their leaves. D) are able to continue producing sugars even when they must close their stomata to reduce water loss during hot days. E) are able to reduce water loss by producing more rubisco.

B

During DNA replication, each strand serves as a _____________ for the new ________________ strand. A) template; supplementary B) template; complementary C) proofreader; complementary D) blueprint; template E) master model; identical

B

During meiosis but NOT during mitosis, A) two identical daughter cells are produced. B) genetic variation among the daughter cells is increased. C) chromosomes line up in the center of the cell during metaphase. D) duplication of the cytoplasm occurs. E) haploid gametes are produced that are all identical in their allelic composition.

C

During meiosis, chromatin A) unwinds to allow synapsis between homologous pairs of chromatids. B) binds to the metaphase plate, enabling chromosome division. C) condenses, becoming more tightly coiled. D) unwinds to allow tetrads to form. E) reduces the incidence of crossing over.

D

During which phase of the cell cycle do the chromosomes align in one plane at the center of the cell? A) prophase B) telophase C) interphase D) metaphase E) anaphase

A

Interacting systems of molecules enclosed in compartments called __________ evolved 3.8 billion years ago in living organisms. A) cells B) organs C) microspheres D) brains E) circulatory systems

E

Is it possible for a woman to have an X-linked recessive trait? If it is, how can this occur? A) No, women cannot have X-linked recessive traits because they are all recessive and women have two X chromosomes. B) Yes, a woman can have an X-linked recessive trait if both her father has the trait and her mother is homozygous for the trait. C) Yes, a woman can have an X-linked recessive trait if both her father has the trait and her mother is heterozygous for the trait. D) Yes, a woman can have an X-linked recessive trait if her mother is homozygous for the trait. E) Both the second and third answer choices are correct.

D

Linked genes A) must be immediately adjacent to each other on the same chromosome. B) have alleles that assort independently of each other. C) never show crossing over. D) are on the same chromosome. E) never have multiple alleles.

E

Which one of the following organelles is NOT found in both plant and animal cells? A) nucleus B) peroxisome C) mitochondrion D) smooth endoplasmic reticulum E) central vacuole

E

Which statement about phospholipids is FALSE? A) They are hydrophobic on one end. B) They are a major constituent of cell membranes. C) They are hydrophilic at one end. D) They contain glycerol linked to fatty acids. E) Because their phosphate groups repel each other, they are used as organisms' chief form of short-term energy

A

Which statement is NOT part of the modern cell theory? A) The first cell arrived on Earth from outer space. B) All living organisms consist of one or more cells. C) Cellular reactions include both energy-releasing and biosynthetic types. D) Cells arise from other cells. E) Cells contain hereditary information that passes from one generation of cells to the next.

E

Which term refers to the genetic control of continuously varying traits such as height? A) multi-allelic B) pleiotropic C) incomplete dominance D) codominant E) polygenic

E

Within interphase, which of the stages is defined by the active replication of the cell's genetic material? A) the Gap 1 phase B) the Gap 2 phase C) the mitotic phase D) the replitosis phase E) the S (DNA synthesis) phase

A

You are bored at a lunch meeting and surreptitiously place a raisin in your glass of water. The raisin swells to twice its original size. Relative to the water, the raisin must have been A) hypertonic. B) osmotic. C) hypotonic. D) isotonic. E) mesotonic.

B

You measure the concentration of a polar molecule inside and outside of a cell. You find that the concentration is high and gradually increasing inside the cell. You also measure the ATP concentration inside the cell and find that it is dropping. Your best hypothesis for the process that is occurring would be A) facilitated diffusion. B) active transport. C) passive transport. D) simple diffusion. E) endocytosis.

C

_________ marks the break in the cell cycle between the end of mitosis and the beginning of the synthesis stage. A) Mitotic phase B) None of the above answer choices is correct. C) Gap 1 D) Gap 2 E) S phase

A

______________ are found in all metabolically active cells and are involved primarily in transporting materials within, into, and out of cells. A) Vesicles B) Lysosomes C) Vacuoles D) Peroxisomes E) Ribosomes

D

A cell is said to have reached the metaphase stage of mitosis when A) the nuclear envelope disappears. B) the cell physically divides in two. C) None of the above answer choices is correct. D) the centromeres have arrived at the equatorial plate. E) separation of the chromatids begins.

C

A cell's interior is considered isotonic to the surrounding fluid when A) the solute concentration is higher within the cell than outside the cell. B) the solute concentration is lower within the cell than outside the cell. C) the solute concentrations are the same within and outside the cell. D) an equal number of water molecules is present immediately outside the cell as inside the cell. E) the cell's lipid bilayer does not allow any molecules to pass into or out of the cell.

E

A cross between homozygous red-eyed flies and homozygous white-eyed flies results in progeny that all have red-eyes. This result demonstrates A) a dihybrid cross. B) the norm of reaction. C) the blending model of genetics. D) the law of independent assortment. E) dominance.

C

A diploid cell undergoes meiosis. What are the products of this division? A) two diploid cells B) one polyploid gamete C) four haploid cells D) two haploid cells E) four diploid cells

A

A diploid individual with two identical alleles for a particular gene is said to be A) homozygous for that gene. B) homozygous for every gene. C) heterozygous for that gene. D) sex-linked dominant. E) heterozygous for every gene.

E

A human skin cell contains 46 chromosomes (23 paternally inherited and 23 maternally inherited). Before mitosis begins, this cell must duplicate its genetic material. What are the products of this duplication? A) 92 chromatids, each consisting of 2 sister chromosomes connected by a kinetochore. B) None of the above answer choices is correct. C) 23 chromosomes, each consisting of a maternal and a paternal chromatid connected by a centromere. D) 92 chromosomes, each consisting of 2 homologous chromatids connected by a centromere. E) 92 sister chromatids, in 46 pairs that are connected by a centromere.

D

A karyotype A) can be produced only from cells in telophase of mitosis. B) requires a haploid gamete. C) reveals the autosomes but not the sex chromosomes. D) can be used to diagnose Down syndrome in humans. E) can be produced only from cells in telophase of mitosis or telophase II of meiosis.

B

A karyotype is a physical representation (usually a photograph) of all of the chromosomes in a single cell; however, the cell must be in mitotic metaphase when the karyotype is made. Why? A) Metaphase is the only stage of the cell cycle in which the nuclear envelope is degraded. B) Metaphase is the only stage of the cell cycle in which the chromosomes have condensed and aligned, but have not yet separated. C) Metaphase is the only stage of the cell cycle in which both sister chromatids of each chromosome are present in the cell. D) Metaphase is the only stage of the cell cycle in which both sets of homologous chromosomes are present in the cell. E) Metaphase is the only stage of the cell cycle in which the cell membrane is permeable to dye.

D

A karyotype of one of your skin cells would reveal a total of 46 chromosomes. How many of these are maternally inherited autosomes? A) 20 B) 46 C) 24 D) 22 E) 23

C

A male with an X-linked recessive disorder mates with a female who is a carrier for this same X-linked recessive disorder. Which of the following is the correct expected frequency of this disorder in their children? A) 50-percent frequency in the sons B) 50-percent frequency in the daughters C) 50-percent frequency in both the sons and the daughters D) 100-percent frequency in the sons E) 100-percent frequency in the daughters

D

A plant with leaves that are reddish yellow is NOT absorbing light from which wavelengths of the visible light spectrum? A) green and red B) blue and violet C) green and yellow D) red and yellow E) green, red, and yellow

D

A plant with pink flowers is allowed to self-pollinate. Generation after generation, it produces pink flowers. This is an example of A) interbreeding. B) allopolyploidy. C) incomplete dominance. D) a true-breeding plant. E) the law of independent assortment.

A

A situation in which the heterozygote offspring of two homozygotes show a phenotype intermediate between those of the parents is called A) incomplete dominance. B) a single-gene trait. C) a testcross. D) heterozygote superiority. E) multiple allelism.

E

A true-breeding red rose is repeatedly mated with a true-breeding white rose, and all of their offspring are red. If two of these red offspring are mated, what percentage of their offspring will be red? A) 60 percent B) 100 percent C) 25 percent D) 50 percent E) 75 percent

D

A unique characteristic of mitochondria is that they are inherited from the female parent only. Select the correct explanation for this phenomenon from the choices below. A) Mitochondria are only found in the female's egg cells and do not occur in male sperm cells. B) Mitochondria are found in both the female's egg cells and the male sperm cells, but the sperm exhaust their mitochondria during their swim up the female's fallopian tubes and are not viable upon fertilization. C) Mitochondria are found in both female egg cells and the male sperm cells, but after fertilization the female mitochondria outcompete the male mitochondria, which then die off. D) Male sperm cells have mitochondria, but because the sperm contributes DNA but no cytoplasm, no mitochondria are passed to the egg at fertilization. E) Mitochondria are found in both female egg cells and the male sperm cells, but the mitochondria from the male sperm cells cannot replicate during the early mitotic divisions in the embryo.

A

A woman with type B blood and a man with type A blood could have children with which of the following phenotypes? A) A, B, AB, or O B) A, B, or O C) AB or O D) O only E) AB only

C

According to the theory of endosymbiosis, the origin of chloroplasts probably involved A) the formation of colonies of cyanobacteria. B) the formation of cell walls around the photosynthetic pigments. C) engulfing of small photosynthetic prokaryotes by a larger cell. D) the accumulation of free oxygen in ocean waters. E) All of the above answer choices are correct

A

Active transport, the movement of molecules from areas of low concentration to areas of high concentration across the membrane, is usually coupled to processes that A) cost energy. B) gain energy for the cell. C) establish a dynamic equilibrium with no net gain or loss in energy for the cell. D) counteract osmotic stress. E) amplify cellular response to signal molecules.

B

Albinism (lack of skin and hair pigmentation) is caused by a recessive autosomal allele. A woman and man, both normally pigmented, have an albino child together. For this trait, what is the genotype of the albino child? A) It is heterozygous. B) It is homozygous recessive. C) It is homozygous dominant. D) It is unknown because not enough information is provided. E) It depends on the sex of the child.

A

All genetically normal humans have A) 44 autosomes. B) 23 chromosomes. C) 46 autosomes. D) 8 toes. E) Two pairs of 22 autosomes, a Y chromosome, and an X chromosome

A

Although cells tend to be spherical, several factors influence cells to assume other shapes. Which of the following does NOT influence cell shape? A) number of mitochondria B) cell walls C) structural filaments within the cells D) pressure from neighboring cells E) the cytoskeleton

B

Anaphase of mitosis occurs when A) the chromatin coils into thicker, visible chromatids. B) the chromatids begin to separate from the metaphase plate. C) crossing over begins. D) the cell enters interphase. E) the nuclear envelope first breaks down.

A

Animal cells have "counters" that keep track of how many times a cell has divided. These counters are called A) telomeres. B) centromeres. C) odometers. D) chromosomes. E) nuclei.

B

Approximately 70-90 percent of the genetic material in a gamete made in your body could be inherited from your mother. How could this be? A) The X chromosome is substantially larger than the Y chromosome. B) You receive many mitochondria, which have their own genome, from your mother, but not from your father. C) Your maternal genes kill off your paternal genes at a greater rate than your paternal genes kill of your maternal genes. D) You receive maternal genes through the placenta and through breast milk. E) The above statement is incorrect because 50 percent of the genetic material in your gametes comes from your father.

D

Assuming that a particular disorder is caused by an allele of a single gene, what feature of a pedigree would allow one to conclude that the disorder was caused by a dominant allele? A) Two unaffected parents have an unaffected child. B) Two unaffected parents have an affected child. C) An affected mother only has affected sons. D) Two affected parents have an unaffected child. E) All of the descendants of a particular affected person are also affected.

C

At locus a, the individual bearing these two homologous chromosomes is A) homozygous for the dominant allele. B) heterozygous for the dominant phenotype. C) homozygous for the recessive allele. D) heterozygous for the recessive allele. E) homozygous for the dominant phenotype.

E

Autosomal dominant traits A) appear in equal frequency in males and females. B) do not skip generations. C) gradually replace autosomal recessive traits. D) All of the above answer choices are correct. E) Both the first and second answer choices are correct.

B

Autosomal recessive traits A) occur in one-quarter of all offspring. B) can skip generations. C) are exhibited only in the offspring of two heterozygous parents. D) occur more frequently in females than males. E) All of the above answer choices are correct.

B

Bacteria reproduce asexually, whereas most plants and animals reproduce sexually. Which is the better method? A) Asexual reproduction is the better method because more bacteria than plants and animals are present. B) Neither method is better—each is effective in different environments for different kinds of organisms. C) Sexual reproduction is the better method because it produces more variation. D) Asexual reproduction is better because binary fission is more efficient. E) Sexual reproduction is the better method because more plants and animals than bacteria are present.

B

Between the stage in the cell cycle where the genetic material is replicated and the process of cell division begins, there is a stage referred to as A) Gap 3. B) Gap 2. C) Gap 1. D) mitotic phase. E) None of the above is correct; there is no stage between the replication and division stages in the cell cycle.

C

Crossing over is the mixing of chromosomes, which results in the recombination of genes on the same chromosome. Which of the following correctly describes the process of crossing over? A) While homologous chromosomes are splitting apart and separating to either end of the new nucleus, two chromosomes switch positions and move toward the ends opposite from where they were originally headed. B) Two alleles exchange positions on a chromosome, creating new recombination frequencies. C) Two chromatids (one maternal and one paternal) break off at corresponding points on homologous chromosomes. The pieces of chromatid rejoin to the chromosome in each other's places. D) During replication, a chromosome from one tetrad breaks off from its pair, as does a chromosome from another tetrad. The two chromosomes switch places. E) One paternal tetrad switches places with a maternal tetrad, so that they occupy places on opposite ends of the spindle fibers.

B

Crossing over means the same as A) sex-linked inheritance. B) the process by which pieces of homologous chromosomes are exchanged. C) incomplete dominance. D) independent assortment. E) heterozygosity.

A

Crossing over takes place during A) meiosis. B) None of the above answer choices is correct. C) mitosis. D) mitosis and meiosis. E) cytokinesis.

B

Cystic fibrosis, which is usually lethal before reproductive ages, is a homozygous recessive disease. Why do cases continue to arise, even though people with the disease rarely live to reproduce? A) Mosquitoes can transfer the disease from person to person. B) The harmful allele can reside in heterozygous individuals with few to no negative effects. C) Individuals can pass on the alleles in non-genetic ways, including through the sharing of needles. D) People continue to make unhealthy lifestyle choices. E) Cystic fibrosis is a multifactorial disorder, and is probably controlled by the action of many genes.

D

Cytokinesis A) results in greater genetic diversity among daughter cells. B) occurs during mitosis but not meiosis. C) All of the above answer choices are correct. D) refers to the division of a cell's cytoplasm. E) occurs during prophase.

A

Energy derived from cellular respiration can originate from A) carbohydrates, proteins, and fats. B) fats only. C) proteins only. D) carbohydrates and proteins only. E) carbohydrates only.

C

Errors sometimes occur when DNA duplicates itself. Why might that be a good thing? A) The DNA replication process becomes more fine-tuned, the more errors it makes. B) The rebuilding process proceeds much more quickly when a few errors occur. C) New genes can enter the population and be acted upon by evolution. D) Errors in DNA replication can never be a good thing. E) Most errors are, in fact, good for the organism in which they occur.

C

Eukaryotic cells can divide by A) synthesis only. B) mitosis only. C) both mitosis and meiosis. D) fission only. E) meiosis only.

C

Eukaryotic cells may contain all of the following EXCEPT A) photosynthetic pigments. B) flagella. C) a peptidoglycan cell wall. D) ribosomes. E) a membrane-bound nucleus

C

Flower color in snapdragons is an example of incomplete dominance. When a red-flowered plant is crossed with a white-flowered plant, the offspring have pink flowers. If a pink-flowered plant is crossed with another pink-flowered plant, their offspring will be A) all red. B) 25 percent white and 75 percent red. C) 25 percent red, 50 percent pink, and 25 percent white. D) 50 percent pink and 50 percent red. E) all pink.

C

Genes that are _____________ do not assort independently, but they may recombine by crossing over. A) continuously variable B) pleiotropic C) linked D) polygenic E) epistatic

B

Given that a cell's structure reflects its function, what would you predict that the function of a cell with a large Golgi apparatus would be? A) movement B) secretion of digestive enzymes C) transport of chemical signals D) rapid replication of genetic material and coordination of cell division E) attachment to bone tissue

C

Glycolysis A) is also referred to as the Krebs cycle. B) is performed solely on the glucose ingested by the organism. C) occurs in all cells. D) is not performed in plants, which get their energy solely through photosynthesis. E) completely oxidizes glucose to carbon dioxide.

A

Glycoproteins are membrane proteins with bound A) carbohydrates. B) nucleic acids. C) signaling peptide sequences. D) phospholipids. E) cofactors

B

Gray hair in voles (H) is dominant to brown hair (h). Short claws (C) are dominant to long claws (c). What is the probability that the offspring of the cross HhCc × HHcc will have gray hair and long claws? A) 0 percent B) 50 percent C) 37.5 percent D) 25 percent E) 56.25 percent

D

Gregor Mendel performed his famous experiments on A) hawkweed. B) humans. C) Darwin's finches. D) garden peas. E) pigeons.

C

Hermaphrodites are individuals with functioning male and female reproductive organs capable of producing both male and female gametes. Which of the following statements about hermaphrodites is INCORRECT? A) An XXY human is a hermaphrodite. B) Hermaphrodites are common among invertebrates. C) Some vertebrate hermaphrodites exist. D) Humans with Klinefelter syndrome are not hermaphrodites. E) No human hermaphrodites exist.

D

How are lysosomes distributed between different types of eukaryotic cells? A) Every different cell type has the same uniform number of lysosomes. B) The functions of lysosomes do not vary depending on cell type. C) Cells, such as white blood cells, do not need lysosomes, because they engulf bacteria on their own. D) Cells that process a lot of larger nutrients, such as liver cells, have larger amounts of lysosomes than other cells. E) Both the first and second answer choices are correct.

A

How are phospholipid molecules that make up the surface membrane of a cell organized? A) A two-layered structure is formed, with the hydrophobic tails facing in to each other, sandwiched between the hydrophilic heads that face the interior of the cell and the exterior environment. B) A single-layered structure is formed, with the hydrophobic tails facing in to the interior of the cell and the hydrophobic head on the outside, facing the exterior environment. C) A single-layered structure is formed, with the hydrophobic heads facing in to the interior of the cell and the hydrophobic tails on the outside, facing the exterior environment. D) A two-layered structure is formed, with the hydrophobic heads facing in to each other, sandwiched between the hydrophilic tails on the outside that face interior of the cell and the exterior environment. E) Both the second and fourth answer choices are possible.

E

How can an individual whose parents did not have the "fish odor syndrome" trait inherit that trait? A) If each parent were a silent carrier of the "fish odor syndrome," then their offspring would have a 100-percent chance of having the syndrome. B) If each parent were a silent carrier of the "fish odor syndrome," then their offspring would have a 50-percent chance of having the syndrome. C) Under the circumstances outlined above, the "fish odor syndrome" cannot be inherited. D) The "fish odor syndrome" trait is inherited extra-genetically. E) If each parent were a silent carrier of the "fish odor syndrome," then their offspring would have a 25-percent chance of having the syndrome.

B

How can two pea plants that have different genotypes for seed color be identical in phenotype? A) One of the two plants could be homozygous for the dominant allele, while the other could be homozygous for the recessive allele. B) One of the two plants could be homozygous for the dominant allele, while the other could be heterozygous. C) Genotype has no relation to phenotype. D) Seed color in pea plants is not genetically determined. E) One of the two plants could be homozygous for the recessive allele, while the other could be heterozygous.

E

In female gamete development in humans and other vertebrates, the net result of meiosis is the production of one large egg and three small cells with very little cytoplasm. These three small cells A) fertilize the egg. B) act to nurse the egg cell. C) divide to form secondary egg cells. D) fuse together to form the placenta. E) degrade almost immediately.

C

How many human traits are controlled by a single gene? A) 2 B) over 100,000 C) over 9000 D) 0 E) about 100

A

How many rotations of the Calvin cycle are required for the production of one glucose molecule? A) 6 B) 12 C) 8 D) 3 E) 2

B

How many sex chromosomes does the normal human female inherit from her mother? A) 2 B) 1 C) 46 D) 22 E) 23

C

How many unique haploid gametic genotypes could be produced through independent assortment by an organism with the diploid genotype AABbCCDdEe? A) 16 B) 1 C) 8 D) 2 E) 4

D

If a baby has "his father's nose," it's because the baby has A) inherited the "father's nose" allele from his mother. B) not inherited the "suppress father's nose allele" from his mother. C) inherited the "father's nose" allele from his father. D) inherited many alleles from his father that work together to shape the baby's nose. E) been cobbled together from a bunch of used parts.

B

If a cell becomes arrested within the cell cycle because it is unable to replicate its DNA, in which of the stages would you predict it would become arrested? A) mitotic phase B) Gap 1 phase C) S phase D) Gap 2 phase E) None of the above is correct; the cell would simply die.

B

If a true-breeding blue-flowered plant was crossed with a true-breeding white-flowered plant, what phenotypic ratio would we observe in the progeny resulting from this cross? Assume the white-flowered trait is completely dominant. A) 100 percent blue B) 100 percent white C) 75 percent blue, 25 percent white D) 100 percent light blue E) Not enough information is provided to answer this question.

E

If the concentrations of a particular molecule are equal on both sides of the membrane, facilitated diffusion will A) ensure that the molecule becomes concentrated inside the cell. B) ensure that the molecule becomes concentrated outside the cell. C) ensure that the molecule stays impermeable to the membrane. D) ensure that the concentrations inside and outside the cell are both increased. E) be ineffective.

A

If the solution surrounding a cell contains less solute than the cytoplasm, the osmotic condition is said to be A) hypotonic. B) hypertonic. C) isotonic. D) isobaric. E) adiabatic.

C

If two individuals who are heterozygous for the sickle-cell disease mate, their offspring will A) all have the genotype HbSHbA. B) have the sickle-cell disease. C) have a one-quarter chance of being a sickle-cell-free homozygote. D) all be heterozygous for the sickle-cell disease. E) None of the above answer choices is correct.

D

In DNA replication, when the DNA molecule separates into two strands, A) the rebuilding process begins, in which an enzyme connects the appropriate complementary base to the exposed base. B) the mitotic phase begins. C) it is possible to reconstruct perfectly all the information on the missing strand because one strand carries all the information needed to construct its complementary strand. D) Only the first and second answer choices are correct. E) All of the above answer choices are correct.

B

In a cell in which 2n = 46, the independent assortment of chromosomes during meiosis can by itself give rise to how many genetically different gametes? A) 23 B) 92 C) 184 D) There is insufficient information to answer this question. E) 46

B

In aquatic environments, water moves A) up the concentration gradient. B) down the concentration gradient. C) down the concentration scale. D) up the concentration scale. E) against the concentration gradient.

C

In asexual reproduction, daughter cells inherit their DNA from A) two separate parents. B) a single offspring. C) a single parent. D) None of the above is correct; in asexual reproduction, the DNA is not inherited. E) multiple offspring.

B

In certain plants, red flowers are dominant to white flowers. If a heterozygous plant is crossed with a homozygous red-flowered plant, what is the probability that the offspring will be white-flowered? A) 25 percent B) 0 percent C) 50 percent D) 100 percent E) It depends on whether the traits are linked.

A

In eukaryotic cells, vesicles connect which of the two major organelle compartments? A) the rough endoplasmic reticulum and smooth endoplasmic reticulum B) the rough endoplasmic reticulum and nucleus C) the smooth endoplasmic reticulum and the peroxisomes D) the rough endoplasmic reticulum and the centrioles E) the rough endoplasmic and the ribosomes

D

In genetics, the separation of alleles or homologous chromosomes during meiosis so that the haploid daughter cells have one allele or the other, but never both, is also referred to as A) Mendel's first law. B) segregation. C) random genetic drift. D) Both the first and second answer choices are correct. E) All of the above answer choices are correct.

A

In humans, X-linked traits A) occur on the X-chromosome. B) are passed from fathers to their sons. C) are more common than autosomal traits. D) occur more frequently in females. E) All of the above answer choices are correct.

D

In humans, both sexes have the same number of autosomes but different ratios of sex chromosomes. Males are XY and females are XX. Which of the following statements comparing the X and Y chromosomes is FALSE? A) The Y chromosome is much smaller than the X chromosome, with 85 genes and 1,000 genes respectively. B) Certain regions on the Y chromosome are unique and not found on the X chromosome. C) Certain regions on the Y chromosome are identical to the genes on the X chromosome. D) Genetic instructions on the X chromosome instruct the fetal gonads to develop as testes instead of ovaries. E) Genetic instructions on the Y chromosome instruct the fetal gonads to develop as testes instead of ovaries.

B

In humans, the haploid number, n, equals A) 2n. B) 23. C) 3n. D) 44. E) 46.

D

In many species of birds, males are XX and females are XZ. With birds like this, who is most likely to display a sex-linked recessive trait? A) Males and females are equally likely to display a sex-linked recessive trait. B) The gender that is incubated at a higher temperature is more likely to display a sex-linked recessive trait. C) No Y chromosome exists, so they are not affected by sex-linked recessive traits. D) Females are more likely to display a sex-linked recessive trait. E) Males are more likely to display a sex-linked recessive trait.

E

In mitosis, telophase occurs when A) crossing over occurs. B) chromosome condensation occurs. C) the chromosomes begin to uncoil. D) the chromosomes reach opposite poles and stop moving. E) Both the first and second answer choices are correct.

E

In most bacteria, the DNA is carried in A) multiple circular chromosomes. B) a single linear chromosome. C) two circular chromosomes. D) multiple linear chromosomes. E) a single circular chromosome

A

In order for a eukaryotic cell to undergo reproduction and divide, certain steps must be successfully completed. Select the choice below that is NOT one of these necessary steps. A) Proper reshuffling of the genetic material must occur in order to provide diversity within the gametes. B) All of the above answer choices are necessary steps in eukaryotic cellular replication. C) Proper packaging and segregation of the replicated DNA must occur. D) Proper division of the cytoplasm must occur. E) Replication of the DNA within the nucleus must occur.

E

In pea plants, purple flower color is dominant to white flower color. If two pea plants that are true-breeding for white flowers are crossed, in the offspring A) all of the flowers will be purple. B) three-quarters of the flowers will be purple and one-quarter will be white. C) half of the flowers will be purple and half will be white. D) one-quarter of the flowers will be purple and three-quarters will be white. E) all of the flowers will be white.

D

In pea plants, tall stem length is dominant to short, and round seed shape is dominant to wrinkled seed shape. If a plant that is homozygous for tall stem and homozygous for wrinkled seeds is allowed to self-fertilize, what proportion of the offspring will have wrinkled seeds and a tall stem? A) 3/16 B) 9/16 C) 1/2 D) All of the offspring will have wrinkled seeds and a tall stem. E) None of the offspring will have wrinkled seeds and a tall stem.

C

In pea plants, the allele for purple flower color is dominant to the allele for white flower color. If you were to perform a testcross to determine the genotype of a purple-flowered plant, you would expect the percentage of purple-flowered progeny to be _________ if the plant is homozygous and _____________ if the plant is heterozygous. A) 50 percent; 25 percent B) 75 percent; 75 percent C) 100 percent; 50 percent D) 100 percent; 25 percent E) 50 percent; 100 percent

A

In snapdragons, flower color is inherited as a trait with incomplete dominance. There is an allele, CW, that produces no pigment, and an allele, CR, that produces red pigment. A plant with the CWCR genotype will produce _________________ flowers. A) pink B) no C) white D) two kinds of E) red

A

In snapdragons, there is an allele for flower color, CW, that produces no pigment. A plant with the genotype CWCW will produce _____________ flowers. A) white B) pink C) purple D) red E) no

A

In some species, sex is determined by environmental, instead of genetic, factors. This is TRUE of A) turtles. B) birds. C) humans. D) bees. E) dogs.

A

In the ______________ process of DNA replication, each of the single strands becomes a double strand as an enzyme connects the appropriate complementary base to the exposed base. A) rebuilding B) duplication C) unwinding D) attachment E) error correction

B

In the case of Mendel's peas, a single gene determined the height of the plant; however, in humans, adult height is influenced by many genes. A trait such as human height is said to be A) codominant. B) polygenic. C) multi-allelic. D) incompletely dominant. E) pleiotropic.

D

In which organelle are lipids synthesized and modified within the eukaryotic cell? A) the Golgi apparatus B) the vesicle C) the rough endoplasmic reticulum D) the smooth endoplasmic reticulum E) the lysosome

E

Mammalian cells take in many molecules including hormones, antibodies, and blood proteins. This process is coordinated by proteins that recognize their specific target molecule. This process is best described as A) phagocytosis. B) pinocytosis. C) exocytosis. D) active transport. E) receptor-mediated endocytosis.

B

Mary, who has type O blood, is expecting a child with her husband, who has type B blood. Mary's husband's father has type A blood. What is the probability that the child will have type O blood? A) 0 percent B) 50 percent C) 100 percent D) 25 percent E) 75 percent

D

Membrane-bound vesicles containing a substance synthesized by a cell fuse to the outer cell membrane and release their contents to the outside world. What is this process called? A) endocytosis B) excretocytosis C) phagocytosis D) exocytosis E) pinocytosis

C

Mendel's law of independent assortment states that the alleles at one locus separate independently of those at other loci. This law does not apply A) if recombination between the two loci occurs. B) to identical twins. C) to genes located close together on the same chromosome. D) to genes that influence the same character. E) to autosomal genes.

D

Mitochondria are thought to have evolved from free-living bacteria that were incorporated into eukaryotic cells by endosymbiosis. Which of the following pieces of evidence for this hypothesis is INCORRECT? A) Mitochondria are enclosed by two membranes instead of a single membrane. B) Mitochondrial DNA is packaged as a single circular chromosome, similar to that of a bacterium. C) New mitochondria are formed by binary fission instead of being replicated during the cell cycle. D) Mitochondria can survive and reproduce independently when removed from the host cell. E) The phospholipid composition of the inner mitochondrial membrane is similar to that of the bacterial cell membrane

D

Mitosis results in A) daughter cells with the same number of chromosomes but different combinations of alleles. B) gametes. C) daughter cells with twice as much genetic material and a unique collection of alleles. D) daughter cells with the same number and composition of chromosomes. E) eight daughter cells.

A

Modern research on male-pattern baldness has confirmed that A) it is a trait passed down to men from their mothers. B) it is caused by clogged hair follicles and toxic hair care products. C) genes on chromosome 20 cause male-pattern baldness. D) balding men commonly share a DNA sequence on their Y chromosome. E) a single maternally inherited allele is the sole contributor of male-pattern baldness.

C

Most genes come in alternative forms called A) dominants. B) recessives. C) alleles. D) chromosomes. E) gametes.

C

Most, if not all, genes are A) codominant. B) multi-allelic. C) pleiotropic. D) heterozygous. E) sex-linked.

D

Naturally occurring chemicals in plants may be useful in inhibiting cancer. One of these chemicals that is found in grapes and peanuts is called A) insulin. B) grape inhibition hormone. C) erythropoietin. D) resveratrol. E) cancer inhibition hormone.

B

Non-disjunction A) is the exchange of genetic material between the chromatids from homologous chromosomes. B) is the unequal division of the genetic material during cell division. C) is the division of cytoplasmic constituents. D) occurs during mitosis but not meiosis. E) is the cause of sex determination in birds and mammals.

A

Nuclear ______ are specialized holes in the ________-layered nuclear envelope that separates the nucleus from the ___________. A) pores; two; cytoplasm B) passageways; one; cytoplasm C) vesicles; three; endoplasmic reticulum D) pores; one; endoplasmic reticulum E) vesicles; two; cytoplasm

A

Osmosis is more/less (pick one) specialized than diffusion because it involves _________. A) more; water B) less; all liquids C) more; acids D) less; acids E) more; bases

B

Peas (Pisum sativum) were well suited for Mendel's breeding experiments for all of the following reasons EXCEPT A) many of the characteristics that vary in pea plants are controlled by single genes. B) peas have a particularly long generation time. C) peas exhibit variations in a number of observable characteristics, such as flower color and seed shape. D) it is easy to obtain large numbers of offspring from any given cross. E) Mendel and his staff could control the pollination between different pea plants.

A

Pedram and Monica are both heterozygous for the widow's peak trait. Individuals who have two copies of the widow's peak allele exhibit a sharp, pointed hairline. What is the probability that the couple's first three children will all have widow's peaks? A) 1/64 B) 1/12 C) 1/4 D) 1/3 E) 3/4

E

Phenotypes are generally a product of A) two or more genes in combination with each other. B) the genotype. C) the environment. D) multiple alleles at the same gene locus. E) the genotype in combination with the environment.

B

Phenylketonuria (PKU) is a disease characterized by the buildup of phenylalanine. The enzyme phenylalanine hydroxylase, which catalyzes the conversion of _________ to __________, is mutated and non-functional. A) arginine; phenylalanine B) phenylalanine; tyrosine C) tyrosine; phenylalanine D) phenylalanine; arginine E) None of the above answer choices is correct.

C

Phenylketonuria is a genetic disorder that causes A) the inability to convert tyrosine to phenylalanine. B) too many copies of phenylalanine to be added to protein chains. C) the inability to convert phenylalanine to tyrosine. D) too few copies of tyrosine to be added to protein chains. E) the buildup of tyrosine in the system.

E

Phenylketonuria is a good example of the environmental effects on phenotype because A) its adverse effects can be avoided by increasing the amount of phenylalanine in the diet. B) some people carry two copies of a mutant version of the gene that is supposed to produce the enzyme that converts phenylalanine to tyrosine. C) its adverse effects can be avoided by increasing the amount of tyrosine in the diet. D) its beneficial effects can be increased by limiting the amount of phenylalanine in the diet. E) its adverse effects can be avoided by limiting the amount of phenylalanine in the diet.

A

Phospholipids assemble spontaneously into bilayers driven by the attraction of their "tail" portions to each other and of their "head" portions to each other. The tail regions are A) hydrophobic. B) cohesive. C) molecularly charged. D) adhesive. E) hydrophilic.

E

Photosynthesis is the process by which plants, some bacteria, and some protistans use the energy from sunlight to produce sugar, which _______________ converts to ATP, the "fuel" used by all living things. A) speciation B) eutrophication C) adaptation D) denaturation E) cellular respiratio

A

Plants have cell walls to give them more structural strength. In order to facilitate movement of molecules from one plant cell to another, channels called ___________________ run through the cell walls. A) plasmodesmata B) plasma membranes C) vacuoles D) transport vesicles E) desmosomes

E

Prokaryotic cells generally have a single circular chromosome attached to A) the ribosome. B) the telomere. C) the nuclear membrane. D) proteins called histones. E) the cell membrane

C

Prokaryotic organisms lack A) cell membranes. B) replicator molecules (DNA or RNA). C) organelles. D) metabolism. E) All of the above answer choices are correct

B

Secretion of cell products such as milk proteins and mucus from glandular cells is accomplished via A) passive transport. B) exocytosis. C) active transport. D) facilitated diffusion. E) endocytosis.

C

Separation of the chromatids at the end of metaphase leads into the next phase, which is A) telophase. B) interphase. C) anaphase. D) postmetaphase. E) prophase.

D

Sex cells having the ___________ number of chromosomes are called ____________. A) haploid; zygotes B) diploid; zygotes C) diploid; somatic cells D) haploid; gametes E) diploid; gametes

A

Sex-linked traits A) often are expressed in different frequencies in males and females. B) occur in males but not females. C) are coded for by genes on the autosomes. D) are coded for by genes on the Y chromosome only. E) occur in females but not males.

E

Somatic cells can include A) kidney cells. B) sperm cells. C) heart cells. D) All of the above answer choices are correct. E) Both the first and second answer choices are correct.

D

Some animals are primarily asexual in their reproduction, but have the ability to switch to sexual reproduction under certain conditions. Why might an animal that generally reproduces asexually make this switch to sexual reproduction? A) None of the above answer choices is correct. B) to confuse its predators C) to better compete in crowded situations D) to increase the genetic diversity of its offspring during periods of stress E) to increase its own likelihood of survival

C

Some fertility clinics now promise that a couple can choose the sex of their baby. What technique might allow for this? A) Separating the father's sperm according to weight, because the X chromosome weighs more than the Y chromosome. B) Add a fluorescent dye to the father's sperm—sperm that show more fluorescence contain an X chromosome. C) Both the first and fourth answer choices are correct. D) Add a fluorescent dye to the father's sperm—sperm that show more fluorescence contain a Y chromosome. E) Separating the father's sperm according to weight, because the Y chromosome weighs more than the X chromosome.

E

Some genes, such as the human ABO blood groups, have more than two alleles. For these genes A) some individuals can be triply heterozygous. B) natural selection cannot alter the allele frequencies. C) a greater proportion of the individuals must be heterozygous than homozygous. D) normal dominance relationships are not possible. E) individuals can only possess two alleles.

D

Sugar and CO2 are dissolved in water to make carbonated soft drinks. Which of the following is the solute? A) the sugar only B) the CO2 only C) the water and the sugar D) the sugar and the CO2 E) the water and the CO2

A

Tay-Sachs, which is a recessive lethal disease, results only when individuals possess two copies of the disease-causing allele. Which of the following statements is TRUE about this disease? A) Heterozygous individuals may pass on their copy of the disease-causing allele to offspring. B) Heterozygous individuals only pass on the dominant copy of the allele to offspring. C) Heterozygous individuals are more fit than homozygous dominant individuals, so eventually, there will only be heterozygotes in the population. D) All cases of this disease must be caused by new mutations. E) None of the above answer choices is correct.

A

The ABO blood type system in humans is a system that contains ________ alleles that produce __________ different phenotypes. A) three; four B) three; six C) four; four D) four; three E) three; three

C

The ABO blood type system in humans is an example of A) balanced polymorphism but not codominance. B) multiple alleles but not codominance. C) multiple alleles and codominance. D) codominance but not multiple alleles. E) balanced polymorphism and codominance.

E

The C4 mechanism of carbon fixation is an advantage for plants that live in A) the shade of other plants. B) cool climates. C) swamps or bogs. D) ponds or other bodies of freshwater. E) hot, dry climates.

B

The DNA in linear eukaryotic chromosomes is wrapped around proteins called _____________, which keep the DNA from getting tangled and enable an orderly, tight, and efficient packing of the DNA inside the cell. A) centromeres B) histones C) histamines D) ribosomes E) telomeres

A

The Gap 1, S (DNA synthesis), and Gap 2 phases of the cell cycle are collectively called A) interphase. B) prephase. C) prophase. D) mitosis. E) anaphase.

C

The MOST IMPORTANT reason that Mendel's law of independent assortment is NOT universally true is that A) genes are almost always pleiotropic. B) half of your genes are inherited from your mother and half from your father. C) genes are carried on chromosomes. D) some genes are sex-linked. E) genes are made of DNA.

A

The SRY gene A) causes fetal gonads to develop as testes shortly after fertilization. B) causes fetal gonads to develop as ovaries shortly after fertilization. C) protect humans from somatic respiratory yeasts. D) causes sickle-shaped red blood cells to resist malaria. E) causes circular red blood cells to resist malaria.

A

The cell connections represented below are A) desmosomes. B) tight junctions. C) gap junctions. D) plasmodesmata. E) lysosomes.

D

The difference in sizes between male and female gametes results from two unequal divisions of __________________ in female gamete development. A) nuclei B) mitosis C) DNA D) cytoplasm E) chromosomes

B

The division of the cytoplasm during cell division is referred to as A) cytoplasm splicing. B) cytokinesis. C) vegetative growth. D) cytodivision. E) hybridization.

A

The egg cells of a horse contain 32 chromosomes. How many chromosomes are in the horse's liver cells? A) 64 B) 16 C) 128 D) 32 E) 8

E

The eukaryotic cell cycle consists of four phases, in the following order A) Gap 1, mitosis, Gap 2, and S (DNA synthesis). B) Gap 1, Gap 2, mitosis, and S (DNA synthesis). C) S (DNA synthesis), Gap 2, Gap 1, and mitosis. D) S (DNA synthesis), mitosis, Gap 1, and Gap 2. E) mitosis, Gap 1, S (DNA synthesis), and Gap 2.

B

The eukaryotic chromosome A) is usually circular. B) consists of two linear strands of double-stranded DNA during the Gap 2 phase. C) condenses only during anaphase of mitosis. D) contains no centromeres. E) consists of a single linear strand of double-stranded DNA during the Gap 2 phase.

B

The failure of a seedling to turn green if grown in the dark is an example of A) interaction between codominant alleles. B) interaction between genotype and environment. C) pleiotropy. D) continuous variation. E) incomplete dominance.

C

The formation of a multicellular organism from a fertilized egg is called development. Development is accomplished through the processes of A) mitosis alone. B) meiosis and cytokinesis. C) mitosis and cytokinesis. D) meiosis alone. E) fission and cytokinesis.

D

The human genome comprises A) a homologous pair of chromosomes. B) 46 pairs of chromosomes. C) 23 chromosomes. D) 46 chromosomes. E) an X and a Y chromosome.

E

The impact of a single gene on more than one characteristic is called A) incomplete dominance. B) epistasis. C) polygenic inheritance. D) codominance. E) pleiotropy.

B

The interphase stage in the eukaryotic cell cycle has the subgroups A) Gap, Synthesis, and Mitotic. B) Gap 1, S phase, and Gap 2. C) Synthesis 1, Synthesis 2, and Synthesis 3. D) Gap 1, Synthesis 1, and Synthesis 2. E) Gap 1, Gap 2, and Gap 3.

B

The largest structure in a eukaryotic cell is the ____________, and it is surrounded by ______ membranes. A) nucleus; one B) nucleus; two C) Golgi apparatus; one D) mitochondrion; two E) mitochondrion; one

C

The law of segregation states that A) gametes cannot be separate and equal. B) an allele on one chromosome will always segregate from an allele on a different chromosome. C) each of two alleles for a given trait segregate into different gametes. D) the transmission of genetic diseases within families is always recessive. E) the number of chromosomes in a cell is always divisible by 2.

E

The light reactions of photosynthesis supply the Calvin cycle with A) sugar and O2. B) light energy. C) free electrons. D) CO2 and ATP. E) ATP, NADPH, and H+.

E

The lipids within the fluid mosaic of the plasma membranes are held in place by A) covalent bonds. B) hydrogen bonds. C) ionic bonds. D) disulfide bridges. E) hydrophobic interactions

D

The lysosomes in a human cell contain approximately ________ type(s) of digestive enzyme(s). A) 1 B) 4 C) 10 D) 50 E) 500

A

The majority of a eukaryotic cell's life is spent in an "in-between-division" stage referred to as A) interphase. B) static phase. C) innerphase. D) S phase. E) dormant phase.

E

The most effective portion(s) of the visible spectrum in driving photosynthesis is/are A) the violet-blue portion. B) Both the first and second answer choices are correct. C) the red-orange portion. D) the yellow-green portion. E) Both the first and third answer choices are correct

C

The movement of H+ into the stomach represented below is accomplished through A) simple diffusion. B) facilitated diffusion. C) active transport. D) endocytosis. E) osmosis.

A

The net movement of molecules from locally concentrated regions to uniform distributions is best described as A) diffusion. B) concentration gradient. C) active transport. D) passive transport. E) enthalpy.

D

The number of chromosome pairs in a species is A) greatest among amphibians. B) always 23. C) greatest among insects. D) None of the above answer choices is correct. E) always greater than three.

D

The offspring from each cross done in Mendel's pea experiments always looked like one of the two parental varieties because A) many different genes interacted to produce the F1 phenotype. B) each allele affected phenotypic expression. C) many different genes interacted to produce the parental phenotype. D) one allele showed complete dominance over the other. E) the traits blended together because of crossing over in meiosis.

C

The only situation in which a person can survive without one of a pair of chromosomes is A) Monosomy 21, in which a person has only one copy of chromosome 21. B) "Metafemales," X_, in which a female has only one sex chromosome. C) Turner syndrome, X_, in which a female has only one sex chromosome. D) "Super Males," Y_, in which a male has only one sex chromosome. E) No situation exists in which a person can survive without one of a pair of chromosomes.

A

The outputs of cellular respiration are A) carbon dioxide, water, and ATP. B) oxygen, carbon dioxide, and ATP. C) oxygen and sugar. D) carbon dioxide, water, and oxygen. E) oxygen, water, and ATP.

B

The passive transport of water across a membrane from a solution of lower solute concentration to a solution of higher solute concentration is best described as A) facilitated diffusion. B) osmosis. C) passive transport. D) active transport. E) general diffusion.

E

The phenotype of an organism can best be determined by A) sequencing its genes. B) inbreeding. C) outbreeding. D) a reciprocal cross. E) observing the organism.

C

The planned process of cell suicide is called A) metastasis. B) malignancy. C) apoptosis. D) meiosis. E) mitosis.

A

The primary function of molecular membranes is the transport of ions and molecules into and out of cells. The movement of molecules from areas of low concentration to those of high concentration against chemical gradients is best described as A) active transport. B) passive transport. C) inactivated transport. D) channel-mediated diffusion. E) electron transport.

A

The primary function of molecular membranes is the transport of ions and molecules into and out of cells—transport is directional and selective. The movement of molecules from areas of high concentration to areas of low concentration to gain energy is best described as A) passive transport. B) active transport. C) inactivated transport. D) channel-mediated diffusion. E) electron transport

A

The principal components of cell membranes are A) lipids. B) proteins. C) carbohydrates. D) nucleic acids. E) glycoproteins.

E

The purpose of mitosis is to enable existing cells to A) generate gametes. B) generate new, genetically diverse cells. C) grow. D) die on purpose. E) generate new, genetically identical cells.

C

The rate at which mitosis occurs varies dramatically for different types of cells. The most rapid cell division occurs A) in the blood and the heart. B) in the gametes. C) in the blood and the cells lining the various tissues of organs. D) on the skin. E) in the heart and the brain.

C

The rough endoplasmic reticulum (ER) is the site of protein synthesis and the smooth ER is the site of lipid synthesis. What is the third compartment of the endomembrane system, and what is that compartment's function? A) lysosomes: sacs that export the proteins and lipids out of the cell B) vesicles: packages of proteins surrounded by cell membranes that sort the proteins and lipids for packaging C) Golgi apparatus: finishes the processing of the proteins and sorts them for export out of the cell D) ribosomes: the place of protein transcription E) None of the above answer choices is correct.

C

The same genetic condition that causes sickle-cell anemia can also protect against A) yellow fever. B) cholera. C) malaria. D) hemophilia. E) HIV-AIDS.

E

What are the two major methods of cellular division in eukaryotic cells? A) mitosis and cloning B) meiosis and cloning C) fission and cloning D) meiosis and fission E) meiosis and mitosis

D

The sickle-cell allele is considered to be pleiotropic because it A) is involved in a continuously varying trait: the amount of oxygen delivery. B) is involved in a continuously varying trait: the amount of resistance to malaria. C) has at least two effects: promoting oxygen delivery and protecting against malaria. D) has at least two effects: disrupting oxygen delivery and protecting against malaria. E) is codominant, in that heterozygotes have both circular and sickled red blood cells

D

The testcross A) makes it possible to determine the genotype of an individual of unknown genotype who exhibits the dominant version of a trait. B) is a cross of an individual whose genotype for a trait is not known with an individual who is homozygous recessive for the trait. C) sometimes requires the production of multiple offspring in order to reveal the genotype of an individual whose genotype is unknown. D) All of the above answer choices are correct. E) Both the first and second answer choices are correct.

C

The three different known biochemical pathways organisms will use to photosynthesize include which of the following? A) C2, C4, CAM B) C3, C4, C5 C) C3, C4, CAM D) C3, C5, CAM E) C4, C5, CAM

E

Which of the pictured chromosomes are sex chromosomes? A) X, Y, and 22 B) X only C) All of the pictured chromosomes are sex chromosomes. D) Y only E) X and Y only

D

To absorb large particles, cells engulf them within their plasma membrane in a process called A) transcription. B) translation. C) replication. D) endocytosis. E) exocytosis

C

Trisomy 21 is a consequence of _______________________, the unequal distribution of chromosomes during meiosis. A) recombination B) crossing over C) non-disjunction D) cytokinesis E) chorionic villus sampling

E

Two fruit flies are crossed, resulting in offspring with a 3:1 phenotypic ratio for a particular trait. This suggests A) that the parents were both homozygous for the gene associated with that trait. B) incomplete dominance. C) that one parent had complete dominance for the gene associated with that trait, while the other parent had incomplete dominance. D) that the one parent was heterozygous for the gene associated with that trait and the other parent was homozygous. E) that the parents were both heterozygous for the gene associated with that trait.

E

Using a light microscope, it is easiest to see chromosomes A) during interphase, when they are concentrated in the nucleus. B) in the mitochondria, because they are circular. C) during asexual reproduction. D) during interphase, because they are uncoiled and have a more linear structure. E) during mitosis and meiosis, because the condensed chromosomes are thicker and therefore more prominent.

B

Vesicles A) deposit their protein cargo in an arbitrary fashion throughout the cell. B) bud off from the endoplasmic reticulum. C) fuse with the nucleus membrane to deliver important enzymes, such as polymerase. D) return back to the Golgi apparatus after they have delivered their proteins to be reused. E) Both the second and fourth answer choices are correct.

E

Virtually everyone with ________ has a parent who exhibits the same trait. A) phenylketonuria B) freckles C) color-blindness D) sickle-cell disease E) a cleft chin

C

We say that genes are linked when they A) produce a balanced polymorphism. B) contain multiple alleles. C) are located near each other on a single chromosome. D) are responsible for producing the same protein. E) assort independently.

D

What are the resulting products of the splitting of water in photosynthesis? A) electrons, oxygen, and photons B) electrons and carbon dioxide C) electrons, carbon dioxide, and hydrogen ions D) electrons, oxygen, and hydrogen ions E) electrons and oxygen

E

What are the three different metabolic pathways that are responsible for the production of ATP? A) glycolysis, oxidation, and the Calvin cycle reactions B) None of the above answer choices is correct. C) hydrolysis, active transport, and the light reactions D) substrate inhibition, catabolism, and fermentation E) glycolysis, the reactions on the electron transport chain, and the Krebs (citric acid) cycle

D

What are the two distinct "faces" of the phospholipids that make up the surface membrane of a cell? A) a hydrophilic head and a hydrophobic tail B) a hydrophobic head and a hydrophilic tail C) a phosphate group head and two fatty acid tails D) Both the first and third answer choices are correct. E) Both the second and third answer choices are correct.

A

What is the definition of "female"? A) producing the larger, less motile gamete B) producing more gametes C) producing the smaller, less motile gamete D) producing the larger, more motile gamete E) producing the smaller, more motile gamete

D

What is the main function of the nucleolus? A) It produces enzymes that are then exported to the lysosomes. B) It produces cell adhesion proteins that are then exported to the cell membrane. C) It is the site of photosynthesis in photosynthetic cells. D) It is the site of ribosome-subunit synthesis. E) Its function is not yet known.

B

What is the most important barrier protecting the inner contents of an animal cell with its exterior environment? A) the cell wall B) the cellular membrane C) the cytoskeleton D) the nucleus E) Both the first and second answer choices are correct

C

What is the only cell type in animals that has a flagellum? A) the ovum B) the hair follicle C) the sperm cell D) kidney cells E) liver cells

B

What makes the rough endoplasmic reticulum rough? A) It is covered with cilia. B) It is covered with ribosomes. C) Its surface is highly folded to increase surface area. D) It is covered with tiny flagella. E) It has a high density of receptor proteins in its membrane.

E

When crossing over occurs, _______________ genes usually stay together. A) multi-allelic B) sex-linked C) pleiotropic D) independently assorting E) linked

C

When genetically based traits are inherited independently from each other, this is known as A) pleitropy. B) multi-allelism. C) Mendel's law of independent assortment. D) linkage. E) polygenism.

C

Where are cell membrane components synthesized? A) lysosomes B) vesicles C) endoplasmic reticulum D) nucleus E) Golgi apparatus

D

Whether it is eggs or sperm being produced through meiosis, under normal circumstances, each gamete ends up with A) exactly two copies of each chromosome. B) the same alleles. C) equal amounts of cytoplasm. D) exactly one copy of each chromosome. E) the same number of spindle fibers.

A

Which cellular structure makes it possible for a cell to differ structurally and biochemically from its surroundings? A) plasma membrane B) nucleolus C) nucleus D) endoplasmic reticulum E) cell wall

A

Which of the following BEST defines diffusion? A) net movement of particles from areas of high concentration to areas of low concentration B) net movement of particles from areas of low concentration to areas of high concentration C) net movement of particles between cells D) net movement of particles from a cell into the extracellular matrix E) net movement of fluids from the environment into and out of an organism

B

Which of the following BEST summarizes the differences between osmosis and diffusion? A) Osmosis deals only with acidic liquids. B) Osmosis deals only with water. C) Osmosis deals only with alkaline liquids. D) Diffusion deals only with alkaline liquids. E) Diffusion deals only with water

E

Which of the following CANNOT occur? A) two cousins having identical mitochondrial DNA B) you and your great-grandmother having identical mitochondrial DNA C) you and your full-sibling sister having identical mitochondrial DNA D) you and your full-sibling brother having different nuclear DNA E) None of the above; all of these are possible

A

Which of the following DOES occur during anaphase I of meiosis? A) The chromosomes move toward the poles. B) Microtubules attach to the kinetochores of the homologous chromosomes. C) The centrosomes move to each pole. D) The homologous pairs align at the metaphase plate. E) The homologous pairs move toward the metaphase plate.

D

Which of the following structures is NOT present in the cell membrane? A) a double layer of phospholipids B) transport proteins that form channels through the phospholipid bilayer C) peripheral proteins on the inner and outer surface D) a rigid matrix of actin and tubulin fibers E) carbohydrates attached to peripheral proteins

B

Which of the following are features that distinguish cancer cells from normal cells? A) Normal cells undergo cytokinesis; cancer cells do not undergo cytokinesis. B) Both the second and fourth answer choices are correct. C) Normal cells can divide a finite number of times; cancer cells can divide indefinitely. D) Normal cells have contact inhibition; cancer cells have no contact inhibition. E) Normal cells metastasize; cancer cells do not metastasize.

B

Which of the following cell membrane components are present in plant cells but absent in animal cells? A) phospholipids B) plasmodesmata C) gap junctions D) proteins E) carbohydrates

C

Which of the following cellular components contains hydrolytic enzymes associated with the digestion of macromolecules? A) peroxisomes B) ribosomes C) lysosomes D) centrioles E) None of the above answer choices is correct.

A

Which of the following did Gregor Mendel never see? A) a chromosome B) a stamen C) an F2 generation D) a pea E) a hybrid

D

Which of the following does NOT occur during prophase I of meiosis? A) Crossing over between tetrads occurs. B) Spindle microtubules form. C) Chromosomes begin to condense. D) Homologous pairs of chromosomes align at the metaphase plate. E) A protein structure called a synaptonemal complex forms between the homologues

C

Which of the following does NOT occur during the Calvin cycle? A) consumption of carbon dioxide B) consumption of ATP C) splitting of water D) carbon fixation E) oxidation of NADPH

D

Which of the following does NOT represent a way in which meiosis and mitosis differ? A) The daughter cells of a mitotic division are identical, but those of a meiotic division are not. B) In mitosis, each cell divides only once, but meiosis consists of two successive divisions. C) Mitosis can occur in either haploid or diploid cells, but meiosis occurs only in diploid cells. D) Chromosome replication occurs before mitotic division, but not before meiotic division. E) In anaphase of mitosis, sister chromatids are separated, but in anaphase I of meiosis, homologous chromosomes are separated.

A

Which of the following energy-generating processes is the only one that occurs in all living organisms? A) glycolysis B) None of the above; no energy-generating processes occur in all living organisms. C) gluco-neogenesis D) photophosphorylation E) the Krebs cycle

E

Which of the following facts supports the claim that mitochondria developed from bacteria that were long ago phagocytosed into eukaryotic cells? A) Mitochondria have flagella for motion. B) Mitochondria have proteins for the synthesis of ATP. C) Mitochondria are the "powerhouses" of the cell. D) Mitochondria are small and easily transported across the membrane. E) Mitochondria have their own DNA

B

Which of the following human sex chromosome genotypes is not possible? A) X_ B) Y_ C) XXY D) XX E) XY

D

Which of the following is NOT a characteristic of Turner syndrome? A) some learning difficulties B) underdeveloped ovaries C) web of skin between neck and shoulders D) XX genotype E) short stature

C

Which of the following is NOT a continuously varying trait? A) weight B) eye color C) sickle-cell disease D) height E) skin color

E

Which of the following is NOT a way in which the cell's surface membrane interacts with the exterior environment? A) The cellular surface receives and transmits incoming messages. B) The cellular surface controls which substances enter and leave the cell. C) The cellular surface mediates attachments to other cells. D) The cellular surface mediates interactions with extracellular material. E) The cellular surface organizes the interior organelle organization of the cell.

E

Which of the following is NOT an important structural feature on the surface membrane of an animal cell? A) glycoproteins B) cholesterol C) carbohydrates D) lipid bilayer E) cell wall

B

Which of the following is NOT true of ALL cells? A) They assimilate nutrients. B) They move by means of flagella or cilia. C) They eliminate wastes. D) They synthesize new cellular material. E) They have DNA as their genetic material

A

Which of the following is a cellular characteristic of ALL eukaryotes? A) a nuclear membrane B) a cell wall C) a nucleoid D) few to no organelles in the cytoplasm E) few to no proteins associated with the DNA

A

Which of the following is a correct description of how exocytosis functions in transporting molecules across the cellular membrane? A) Vesicles are filled with molecules in the interior of the cell and then fuse with the membrane to deposit the molecules outside of the cell. B) Protein molecules on the interior of the cellular membrane trap molecules attached on the exterior side and bring them into the cell. C) Nutrients are moved within the cell from one tightly woven network to another. D) A receptor protein on the outside of the cell binds a particular biochemical, causing the membrane to form an indentation, bringing the biochemical into the cell. E) None of the above answer choices is correct

B

Which of the following is a single-gene trait? A) height B) the widow's peak hairline C) brown hair D) blue eyes E) All of the above answer choices are correct.

D

Which of the following would be a typical product of the dark reactions of photosynthesis? A) pyruvate B) green fluorescent protein C) ethanol D) 3-phosphoglycerate acid (3-PGA) E) FADH2

E

Which of the following is an important difference between the rough endoplasmic reticulum and the smooth endoplasmic reticulum? A) The rough endoplasmic reticulum is the site of much protein folding and packaging, whereas the smooth endoplasmic reticulum is the site of lipid synthesis. B) The smooth endoplasmic reticulum is the site of protein synthesis, folding, and packaging, whereas the rough endoplasmic reticulum is the site of lipid synthesis. C) The rough endoplasmic reticulum is covered in ribosomes, whereas the smooth endoplasmic reticulum is not. D) The rough endoplasmic reticulum is studded with chloroplasts, whereas the smooth endoplasmic reticulum is not. E) Both the first and third answer choices are correct.

A

Which of the following is found in both prokaryotic and eukaryotic cells? A) ribosome B) centriole C) Golgi apparatus D) peroxisome E) lysosome

B

Which of the following is the best way to distinguish male from female? A) Males are more brightly colored. B) Males produce motile gametes. C) Males are larger. D) All of the above answer choices are correct. E) Males are more aggressive.

E

Which of the following is the most important factor governing a cell's particular type of interaction with other cells? A) the location of the cell within an organism B) whether or not the cell is eukaryotic or prokaryotic C) whether or not the cell is an animal cell or a plant cell D) the type of animal the cell came from E) the pattern of glycoproteins and glycolipids on the cell's surface

D

Which of the following is the primary site of protein assembly within eukaryotic cells? A) the vesicles B) the Golgi apparatus C) the smooth endoplasmic reticulum D) the ribosomes E) the peroxisome

B

Which of the following organelles are enclosed by a double membrane? A) the nucleus and the Golgi apparatus B) mitochondria and chloroplasts C) ribosomes and lysosomes D) vacuoles and the endoplasmic reticulum E) All organelles are enclosed by a double membrane.

B

Which of the following organelles is responsible for degrading waste within the cell? A) Golgi apparatus B) lysosome C) endoplasmic reticulum D) ribosome E) chloroplast

D

Which of the following pairings, indicated by letters referring to blood type phenotypes, CANNOT produce a child with type B blood? A) O × AB B) A × B C) B × O D) O × O E) All of the above can produce a child with type B blood.

B

Which of the following sequences accurately represents the flow of electrons during photosynthesis? A) H2O → ATP → Calvin cycle B) H2O → NADPH → Calvin cycle C) NADPH → chlorophyll → Calvin cycle D) NADPH → electron transport chain → O2 E) NADPH → O2 → CO2

B

Which of the following statements about dominant traits is CORRECT? A) They are observed less frequently than recessive traits. B) They are observed more frequently than recessive traits. C) They are observed one-quarter as frequently as heterozygous traits. D) They increase in frequency over evolutionary time. E) None of the above answer choices is correct.

E

Which of the following statements about dominant traits is CORRECT? A) They are observed less frequently than recessive traits. B) They are observed more frequently than recessive traits. C) They are observed one-quarter as frequently as heterozygous traits. D) They increase in frequency over evolutionary time. E) None of the above answer choices is correct.

C

Which of the following statements about glycolysis is INCORRECT? A) It results in the oxidation of glucose. B) It occurs in the cytoplasm of the cell. C) It requires oxygen. D) It generates ATP. E) It leads to the formation of pyruvate

C

Which of the following statements about the cell cycle is FALSE? A) A cell can remain in Gap 1 indefinitely. B) It consists of mitosis and interphase. C) The cell's DNA replicates during Gap 1. D) Proteins are formed through all subphases of interphase. E) Histones are synthesized primarily during the S phase.

E

Which of the following statements about the cytoskeleton is FALSE? A) It is responsible for some cellular movement. B) It is made from proteins that act as a scaffolding. C) It is present in both prokaryotic and eukaryotic cells. D) It is a three-dimensional structure that fills the cytoplasm. E) All of the above statements are TRUE.

D

Which of the following statements is INCORRECT regarding human sex chromosomes? A) On average, half a man's sperm carry an X chromosome and half carry a Y. B) X and Y chromosomes differ in structure. C) Gametes produced by females have an X chromosome, but not a Y. D) All diploid cells have both an X and a Y chromosome. E) All diploid cells have at least one X chromosome.

A

Which of the following statements is TRUE regarding pedigree analysis? A) Darkened shapes always represent individuals with the trait being traced. B) Squares represent females, whereas circles represent males. C) White shapes always represent heterozygous individuals. D) Horizontal lines connect siblings. E) The length of the vertical lines is dependent on the relatedness coefficient between two individuals.