Biology Midterm III PRS Clicker Questions

What percent of their male progeny will show the cleft chin trait? A. 0 B. 25 C. 50 D. 75 E. 100

A

An individual with cystic fibrosis must have parents that: A. Both have two dominant genes. B. Both have at least one recessive gene. C. One has one recessive gene, but the other has two dominant genes. D. Have cystic fibrosis.

B

Chromosomes start to condense & the spindle starts to form in A. anaphase B. prophase C. prometaphase D. telophase E. metaphase

B

Diploid organisms use meiosis for the development of gametes. Meiosis consists of how many rounds of nuclear division? A. One B. Two C. Three D. Four

B

During which phase of mitosis do the two sister chromatids become individual chromosomes? A. telophase B. anaphase C. prophase D. metaphase

B

Each chromosome has a ___________, a point of constriction that bind specific proteins and holds two sister chromatids together. A. DNA strand B. centromere C. node D. synapse

B

Homologous chromosomes _____. A. are identical B. carry information for the same traits C. carry the same alleles D. align on the metaphase plate in meiosis II

B

If a trait not expressed in the F1 generation reappears in the F2 generation, the inheritance of the trait in question is a(n) example of A. codominance B. dominance and recessiveness C. incomplete dominance D. epistasis E. a sex linked trait

B

If you wanted to convert a proto-oncogene to an oncogene, which of the following methods would you choose? A. growth factor exposure B. genetic damage C. pair the proto-oncogene with a tumor-suppressor gene D. halt cell cycle progression

B

It has been found that at a certain locus of the human genome, 200 different alleles exist in the population. Each person has at most _______ alleles at this locus A. 1 B. 2 C. 100 D. 200 E. 400

B

Meiosis and mitosis are both processes that involve nuclear division. What is the difference between the two? A. Mitosis is nuclear division, resulting in haploid gametes. Meiosis is nuclear division, resulting in diploid somatic cells. B. Mitosis is nuclear division, resulting in diploid somatic cells. Meiosis is nuclear division, resulting in haploid gametes. C. Mitosis is nuclear division, resulting in diploid gametes. Meiosis is nuclear division, resulting in haploid somatic cells. D. Mitosis is nuclear division, resulting in syngamy. Meiosis is nuclear division, resulting in zygotes.

B

Mendel referred to the trait that was expressed in the hybrid, F1 or first filial generation as A. recessive. B. dominant. C. codominant. D. independent.

B

Plant cells typically achieve cytokinesis by A. binary fission. B. forming a cell plate across the middle of the cell. C. forming a cleavage furrow that pinches the cell into two. D. chromosome elongation.

B

Proteins that are involved in the regulation of the cell cycle, and that show fluctuations in concentration during the cell cycle, are called A. Cdks. B. cyclins. C. kinetochores. D. ATPases.

B

The initiation of the S phase and the M phase of the cell cycle depends on a pair of molecules called _______ and _______. A. actin; myosin B. Cdks; cyclin C. ligand; receptor D. ATP; ATPase

B

The two copies of each chromosome in body cells are called A. sister chromatids. B. homologous chromosomes. C. sister chromosomes. D. daughter chromosomes. E. genes.

B

Let P = purple flowers and p = white, and T = tall plants and t = dwarf. Of the 16 possible gamete combinations in the dihybrid cross, how many would be the phenotype white, tall A. None B. 1 C. 3 D. 9

C

Crossing over involves the exchange of genetic material between A. sister chromatids B. males and females C. sex chromosomes D. homologous chromosomes

D

Cyclin-dependent kinase (Cdk) is _____. A. inactive, or "turned off," in the presence of cyclin B. present only during the S phase of the cell cycle C. the enzyme that catalyzes the attachment of chromosomes to microtubules D. an enzyme that attaches phosphate

D

Cytokinesis occurs right after A. prophase B. G2 C. anaphase D. telophase

D

During which phase of the cell cycle are mitochondria and chloroplasts distributed equally among daughter cells? A. G2 B. M C. C D. There is no mechanism to distribute mitochondria and chloroplasts equally among daughter cells.

D

In Netherlands dwarf rabbits, a gene showing intermediate inheritance produces three phenotypes. Rabbits that are homozygous for one allele are small rabbits; individuals homozygous for the other allele are deformed and die; heterozygous individuals are dwarf. If two dwarf rabbits are mated, what proportion of their surviving offspring should be dwarf? A. 1/4 B. 1/3 C. 1/2 D. 2/3 E. 3/4

D

In a simple Mendelian monohybrid cross, true-breeding tall plants are crossed with short plants, and the F1 plants, which are all tall, are allowed to self-pollinate. What fraction of the F2 generation are both tall and heterozygous? A. 1⁄4 B. 1⁄3 C. 2⁄3 D. 1⁄2

D

In guppies, fan tail is dominant to flesh tail, and rainbow color is dominant to pink. F1 female guppies are crossed with flesh-tailed, pink-colored males, and the following progeny are observed: 98 fan-tailed, pink-colored; 102 flesh-tailed, rainbow-colored; 399 flesh-tailed, pink-colored; and 401 fan-tailed, rainbow-colored guppies. Assuming that the F1 female guppies have both dominant alleles on one chromosome, the map distance between these two genes is A. 80 cM B. 25 cM C. 0.8 cM D. 20 cM E .None of the above

D

Let P = purple flowers and p = white, and T = tall plants and t = dwarf. What combinations of gametes could be produced by a heterozygote for both the traits A. PpTt only B. Pp, Tt C. P, p, T, t D. PT, Pt, pT, pt

D

Sister chromatids separate from each other during A. meiosis I only B .meiosis II only C. mitosis and meiosis I D. mitosis and meiosis II

D

A dominant allele K is necessary for normal hearing. A dominant allele M on a different locus results in deafness no matter which other alleles are present. If a kkMm individual is crossed with a Kkmm individual, _______ percent of the offspring will be deaf. A. 0 B. 25 C. 50 D. 75 E. None of the above

I think D

In pea plants, the gene for yellow seeds, Y, is dominant to the allele for green seeds, y. A plant with green seeds must have the genotype A. YY B. Yy C. yy D. XY

C

One of the main reasons genes assort independent of one another is that A. they produce unrelated traits. B. they are on the same chromosome. C. they are different alleles. D. they are on different chromosomes.

D

A man who carries an allele of an X-linked gene will pass it on to _____. A. all of his daughters B. half of his daughters C. all of his sons D. all of his children

A

E. coli, which doubles every 20 minutes weighs 10-12 g, while the Earth 6 x 1024 kg. At this rate, how long before E. coli would outweigh the Earth? A. 1-2 days B. 1 week C. 1 month D. 1 year E. 1 decade

A

In Mendel's experiments, if the allele for tall (T) plants was incompletely dominant over the allele for short (t) plants, what offspring would have resulted from crossing two Tt plants? A. 1/4 tall; 1/2 intermediate height; 1/4 short B. 1/2 tall; 1/4 intermediate height; 1/4 short C. All the offspring would have been tall D. All the offspring would have been of intermediate height

A

In white tigers, the absence of fur pigmentation is caused by a recessive allele. This allele also causes the tigers to be cross-eyed. If two tigers heterozygous for this allele mate and produce offspring, what percentage can be expected to be white and/or cross-eyed A. 25% will be white and the same 25% will be cross-eyed B. 25% will be white and 25% will be cross-eyed, but not necessarily the same 25% due to independent assortment C. 50% will be both white and cross-eyed D. Because it is a recessive allele, none of the offspring in the F1 generation will be white or cross-eyed

A

Mature nerve cells are incapable of cell division. These cells are probably in A. G1 B. the S phase C. G2 D. mitosis

A

Meiosis is used primarily A. to produce haploid gametes B. by animals but not plants C. for asexual reproduction D. to take a pause from the cell cycle

A

The bacterial genome exist as a A. single, circular, double stranded DNA molecule. B. single, circular, double stranded RNA molecule. C. single, linear, double stranded DNA molecule. D. many, circular, double stranded DNA molecules.

A

The likelihood that a child will inherit cystic fibrosis if his or her parents each have one recessive gene is approximately: A. 1 in 4 (25%) B. 2 in 4 (50%) C. 3 in 4 (75%) D. 4 in 4 (100%)

A

The phenotypic ratio for a testcross with a homozygous individual and a heterozygous individual is ______. A. 1:1 B. 2:1 C. 3:1 D. 1:2:1

A

The totality of the alleles present in an organism is called its A. genotype B. heterozygote C. homozygote D. phenotype

A

True breeding plants A. produce the same offspring when crossed for many generations B. result from a monohybrid cross C. result from a dihybrid cross D. result from crossing over during prophase I of meiosis

A

Unattached earlobes are a dominant trait. Finn and Maggie both have unattached earlobes but their daughter, Celia, does not. If Finn and Maggie have a second child, what is the probability that it will have attached earlobes? A. 1⁄4 B. 1⁄2 C. 3⁄4 D. 1⁄8

A

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

A

Where do cells spend most of their time? A. Interphase B. Mitosis C. Cytokinesis D. Meiosis

A

Which of the following is not true of homologous chromosome pairs? A. They come from only one of the individual's parents B. They usually contain slightly different versions of the same genetic information C. They segregate from each other during meiosis I D. They synapse during meiosis I E. Each contains two sister chromatids at the beginning of meiosis I

A

Which statement best explains the way that an abnormal p53 causes normal cells to become cancer cells? The abnormal p53 protein A. fails to carry out DNA repair. B. triggers too many cells to grow. C. damages the normal DNA. D. stimulates the death of normal cells. E. enhances tumor-suppressor genes.

A

When cyclin binds Cdk, A. the cell transitions from G2 to S B. kinase activation can occur C. chromosomes condense D. the cell quickly enters M phase

B

Which of the following statements about crossing over is false? A. Crossing over takes place between non-sister chromatids. B. Crossing over takes place between sister chromatids. C. Recombination nodules may be observed. D. Sites of crossing over are called chiasmata.

B

Y-linked genes include a gene that produces hairy pinnae (the external ear). A male with hairy pinnae will pass this trait A. to his sons and daughters B. only to his sons C. only to his daughters D. only to his grandsons E. to all his children if the mother is a carrier

B

Yellow-seeded plants might be homozygous or heterozygous. We could find out which by crossing these plants with A. true breeding yellow-seeded plants. B. true breeding green-seeded plants. C. heterozygous yellow-seeded plants. D. true breeding white-flowered plants. E true breeding purple-flowered plants

B

You are studying meiosis in an organism that has 28 chromosomes as its diploid number. How many chromosomes will each nucleus have after meiosis I, but before cytokinesis A. 7 B. 14 C. 28 D. 56

B

Mitosis is most like __________. A. Meiosis I B. Meiosis II

Both can be argued

Animal cells typically achieve cytokinesis by A. binary fission. B. forming a cell plate across the middle of the cell. C. forming a cleavage furrow that pinches the cell into two. D. chromosome condensation. E. chromosome elongation.

C

At the end of cytokinesis II of meiosis, each of the four resulting cells contains A. one full set of chromosomes, each with two chromatids. B. two full sets of chromosomes, each with two chromatids. C. one full set of chromosomes, each a single chromatid. D. two full sets of chromosomes, each a single chromatid. E. a different number of chromosomes.

C

At the end of meiosis and cytokinesis, each of the four resulting cells contains A. one full set of chromosomes, each with two chromatids. B. two full sets of chromosomes, each with two chromatids. C. one full set of chromosomes, each a single chromatid. D. two full sets of chromosomes, each a single chromatid

C

Classical albinism results from a recessive allele. Which of the following is the expected ratio for the progeny when a normally pigmented male with an albino father has children with an albino woman? A. 3⁄4 normal; 1⁄4 albino B. 3⁄4 albino; 1⁄4 normal C. 1⁄2 normal; 1⁄2 albino D. All normal

C

Crossing spherical-seeded pea plants with wrinkled-seeded pea plants resulted in progeny that all had spherical seeds. This indicates that the wrinkled-seed trait is A. neutral B. dominant C. recessive D. environmental

C

Height and eye colors are two examples of continuous variation in humans. Whereas in pea plants the tall allele is dominant over the short allele, there are no intermediate heights in peas. Which of the following is the best explanation for the differences described above? A. The intermediate size pea plant seeds are aborted within the seedpod and thus will never develop. B. The intermediate size pea plant seeds have deleterious alleles that prevent them from germinating. C. Many genes, rather than one gene for a characteristic, control some variations in species. D. These variations in humans are affected by lack of dominance in the alleles that control these traits.

C

If a bacterial population has 1000 cells and divides every 30 minutes, how many cells will there be in two hours? A. 3,000 B. 4,000 C. 16,000 D. 30,000 E. 60,000

C

In dogs, erect ears and barking while following a scent are due to dominant alleles; droopy ears and silence while following a scent are due to recessive alleles. A dog homozygous dominant for both traits is mated to a droopy-eared, silent follower. The expected F1 phenotypic ratios should be A. 9:3:3:1 B. 8:8 or 1:1 C. 16:0 D. 4:8:4 or 1:2:1

C

In the ABO blood type system, A. A, B, and O are codominant B. A, B, and O are incompletely dominant C. A and B are codominant D. O is incompletely dominant to A and B E. A is dominant to B, and B is dominant to O

C

One difference between mitosis and meiosis I is that A. homologous chromosome pairs synapse during mitosis B. chromosomes do not replicate in the interphase preceding meiosis I C. homologous chromosome pairs synapse during meiosis but not during mitosis D. spindles composed of microtubules are not required during meiosis E. sister chromatids separate during meiosis but not during mitosis

C

Organisms generally have many more genes that assort independently than the number of chromosomes. This phenomenon is due to A. independent assortment. B. segregation. C. crossing over. D. epistasis. E. pleiotropy.

C

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

C

The human X and Y chromosomes _____. A. are both present in every somatic cell of males and females B. are the same size and have the same number of genes C. include genes that determine an individual's sex D. are called autosomes

C

What fraction of offspring of the cross AaBb × AaBb is homozygous for all the dominant alleles, assuming that they are on different chromosomes A. 1⁄4 B. 1⁄8 C. 1⁄16 D. 1⁄32

C

What fraction of offspring of the cross AaBb × AaBb is homozygous for all the dominant alleles, assuming that they are on different chromosomes? A. 1⁄4 B. 1⁄8 C. 1⁄16 D. 1⁄32

C

What is occurring during S phase? A. Nothing, the cell is resting B. Cytokinesis C. DNA synthesis D. Nuclear division

C

What stage is represented by this figure? A. Prophase I B. Metaphase I C. Anaphase I D. Metaphase II E. Anaphase II

C

When the two haploid gametes contain two different alleles of a given gene, the resulting offspring is called A. discrete. B. a haploid. C. heterozygous. D. homozygous.

C

Which is the first and primary checkpoint in the cell cycle where a cell will be caused to exit the cycle if this point is not passed? A. G2/M B. S/G2 C. G1/S D. M/Cytokinesis

C

Which of the following describes the ability of a single allele to have multiple phenotypic effects? A. Incomplete dominance B. Multiple alleles C. Pleiotropy D. epistasis

C

Which of the following is a protein maintained at constant levels throughout the cell cycle that requires cyclin to become catalytically active? A. Cyclin B. protein kinase C. Cdk D. MPF

C

Which of the following statements about Mendelian genetics is false? A. Alternative forms of genes are called alleles B. A locus is a gene's location on its chromosome C. Only two alleles can exist for a given gene in a population D. A genotype is a description of the alleles that represent an individual's genes E. Individuals with the same phenotype can have different genotypes

C

You are studying meiosis in an organism that has 28 chromosomes as its diploid number. How many chromosomes will the cell have after meiosis II, but before cytokinesis? A. 7 B. 14 C. 28 D. 56

C

A chromatid is A. one of the pairs of homologous chromosomes. B. a homologous chromosome. C. a newly replicated bacterial chromosome. D. one-half of a newly replicated eukaryotic chromosome.

D

A person with cystic fibrosis must have: A. Two working CTFR genes. B. One working CTFR gene and one faulty gene. C. One working CTFR gene and one completely nonworking gene. D. Two CTFR genes that are not working correctly.

D

A person without cystic fibrosis must have: A. One dominant CTFR gene and one recessive CTFR gene B. Two dominant CTFR genes C. Two recessive CTFR genes D. They can have options A or B

D

A test cross can be used to do all of the following except A. determine whether an individual that displays a dominant phenotype is homozygous for the trait. B. determine whether an individual that displays a dominant phenotype is heterozygous for the trait. C. gather genotype information from phenotype information. D. identify the chromosome on which a gene is located.

D

An allele that is present but unexpressed is A. redundant. B. dominant. C. epistatic. D. recessive.

D

At the end of the first meiotic division, each chromosome consists of A. chiasmata B. a homologous chromosome pair C. four copies of each DNA molecule D. two chromatids E. a pair of polar microtubules

D

Between the two divisions of meiosis there is A. a full cell cycle. B. a pairing of homologues. C. replication of some parts of the chromosomes. D. no S phase. E. random combination among chromatids.

D

The ABO blood groups in humans are determined by a multiple allelic system in which A and B are codominant, and are dominant to O. If an infant born to a type O mother also is type O, possible phenotypes for the father are A. O or A B. A or B C. O only D. O, A, or B E. impossible to determine

D

The likelihood that a child will inherit cystic fibrosis if his or her parents both have cystic fibrosis is approximately: A. 1 in 4 (25%) B. 2 in 4 (50%) C. 3 in 4 (75%) D. 4 in 4 (100%)

D

Which of the following is essentially the reverse of prophase? A. Anaphase B. Interphase C. Metaphase D. Telophase E. Cytokinesis

D

Which of the following is not true of sister chromatids? A. They arise by replication during S phase B. They segregate from each other during each mitotic anaphase C. They usually contain nearly identical versions of the same genetic information D. They segregate from each other during meiosis I E. They are joined during prophase and metaphase at their common centromere

D

Which of the following is true of sister chromatids? A. They are replicated chromosomes still joined together at the centromere B. They are nearly identical in mitotic chromosomes C. They are nearly identical in meiotic chromosomes D. Both A and B are true E. A, B, and C are all true

D

Which of the following statements about cyclin-dependent kinases (Cdks) or cyclin is false? A. Different Cdks act at different points in the cell cycle. B. A Cdk can catalyze the phosphorylation of other proteins. C. Cdks use ATP as a substrate. D. Cyclin is made continuously during the cell cycle.

D

Which of the following statements best fits as an analogy for a cell with a mutation in a tumor-suppressor gene? A. The gas pedal of a car gets stuck while pushed down. B. The gas pedal of a car does not work at all. C. The brake pedal of a car gets stuck while pushed down. D. The brake pedal of a car does not work at all.

D

Which statement about an individual that is homozygous for an allele is false? A. Each of its cells possesses two copies of that allele B. Each of its gametes contains one copy of that allele C. It is true-breeding with respect to that allele D. Its parents were necessarily homozygous for that allele E. It can pass that allele to its offspring

D

Why do neurons and some other specialized cells divide infrequently? A. They show a drop in MPF concentration. B. They no longer have active nuclei. C. They can no longer bind Cdk to cyclin. D. They have been shunted into G0.

D

A particular cell has half as much DNA as other cells in a mitotically active tissue. The cell in question is most likely in A. anaphase. B. prophase. C. G2. D. metaphase. E. G1.

E

Cleft chin is a sex-linked dominant trait. A man with a cleft chin marries a woman with a round chin. What percent of their female progeny will show the cleft chin trait? A. 0 B. 25 C. 50 D. 75 E. 100

E

In cocker spaniels, black color (B) is dominant over red (b), and solid color (S) is dominant over spotted (s). If the offspring between BBss and bbss individuals are mated with each other, what fraction of their offspring will be expected to be black and spotted? A. 1⁄16 B. 9⁄16 C. 1⁄9 D. 3⁄16 E. 3⁄4

E

The success of DNA replication is assessed during the ______ phase. A. G0 B. G1 C. C D. S E. G2

E