General Biology 1011 Exam 3 Review

If an XY male carries a mutation on his X chromosome, _______________ will receive the mutant X. a. all his sons and daughters b. all of his sons c. all of his daughters d. half his sons and half his daughters

c. all of his daughters

In which phase of mitosis do sister chromatids separate? a. telophase b. metaphase c. anaphase d. prophase

c. anaphase

What cellular process(es) is/are responsible for the increase in protein content associated with the gap phases of the cell cycle? a. translation alone b. glycolysis c. both transcription and translation d. transcription alone

c. both transcription and translation Increased protein content comes most directly from translation, but translation requires RNA produced from transcription, so both are required.

Insertions and deletions of single nucleotides: a. add or delete amino acids to or from the normal polypeptide. b. cause missense mutations. c. cause frameshift mutations. d. shorten chromosomes. e. cause cancer.

c. cause frameshift mutations.

Which of the statements is least likely to produce recombinant chromosomes? a. crossovers between homologous chromosomes b. crossovers between non-sister chromatids c. crossovers between sister chromatids

c. crossovers between sister chromatids

At the end of mitosis the daughter cells are ____________, whereas at the end of meiosis I the daughter cells are ____________. a. haploid; diploid b. polyploid; haploid c. diploid; haploid d. diploid; polyploid

c. diploid; haploid

A skin cell in G2 of interphase has _______________ as much DNA as it had in G1. a. half b. twice c. exactly d. one-fourth e. four times

b. twice

Color blindness is a recessive X-linked trait in humans. In a family where the mother is heterozygous for color blindness and the father is color-blind, the probability of their having a color-blind daughter is: a. 1/2. b. 1. c. 1/16. d. 0. e. 1/4.

a. 1/2.

If two individuals were heterozygous for freckles, which is a dominant trait, what percentage of their progeny would have freckles? (Hint: make dominate freckles F) a. 75% b. 25% c. 100% d. 50%

a. 75%

In a cross between two individuals who are heterozygous for two traits determined by dominant and recessive alleles (Aa Bb), what is the expected ratio of phenotypes for the traits determined by both genes? a. 9:3:3:1 b. 1:1 c. 3:1 d. 12:4:4:1

a. 9:3:3:1

Which of the answer choices occurs during anaphase I of meiosis? a. In males, the X chromosome is segregated from the Y chromosome. b. Homologous chromosomes move as one unit. c. The chromosome number is doubled during this phase of meiosis. d. In females, the two X chromosomes remain together. e. The centromeres of the chromosomes divide.

a. In males, the X chromosome is segregated from the Y chromosome.

_____________produces genetically unique daughter cells a. Meiosis b. Mitosis

a. Meiosis

_________produces genetically identical daughter cells a. Mitosis b. Meiosis

a. Mitosis

For an individual who is heterozygous for two genes, Aa and Bb, what does independent assortment predict? a. Offspring inheriting the dominant (A) allele of the first gene are equally likely to inherit either the dominant (B) or the recessive (b) allele of the second gene. b. Offspring inheriting the dominant allele (A) of the first gene will also inherit the dominant (B) allele of the second gene. c. Offspring inheriting the recessive allele (a) of the first gene will inherit the dominant allele (B) of the second gene.

a. Offspring inheriting the dominant (A) allele of the first gene are equally likely to inherit either the dominant (B) or the recessive (b) allele of the second gene.

A researcher is studying phases of the cell cycle in a population of cells during which there is an increase in the DNA content. This stage is most likely: a. S phase. b. cytokinesis. c. G1 phase. d. mitosis.

a. S phase.

In Drosophila, the red-eye allele for eye color exhibits complete dominance over the recessive white-eye allele. In some of Thomas Hunt Morgan's initial experiments, he crossed red-eyed female flies with white-eyed males. When Morgan crossed the F1 red-eyed heterozygous females with red-eyed males, he found that half of the male progeny were white-eyed. What is the most likely explanation of this result? a. The gene responsible for eye color is on the X chromosome. b. The gene responsible for eye color is on the Y chromosome. c. Chemical factors secreted by males mutated the eye color gene. d. The gene responsible for eye color is on an autosome. e. Chemical factors secreted by males changed the color of the eye.

a. The gene responsible for eye color is on the X chromosome.

Which of the statements is true regarding CDKs? a. The levels of CDKs change with the cell cycle. b. CDKs are active in cells that enter G0 phase of the cell cycle. c. CDKs are active except when they bind to cyclins. d. Loss of CDK activity would lead to cancer.

a. The levels of CDKs change with the cell cycle.

What happens to CDKs in the absence of cyclins? a. They are inactive. b. They become phosphorylated. c. They are degraded. d. They are inactive and become phosphorylated.

a. They are inactive.

The F1 generation of a cross between two individuals, one that is homozygous dominant for a trait and the other that is homozygous recessive for the trait, will yield progeny with the same phenotype. a. True b. False

a. True

Which DNA sequences are more alike: a pair of sister chromatids or a pair of homologous chromosomes? a. a pair of sister chromatids b. a pair of homologous chromosomes

a. a pair of sister chromatids

Segregation of alleles corresponds to the separation of: a. chromosome b. phenotypes c. genotypes. d. genes.

a. chromosome

Mitosis forms ______________daughter cells a. diploid b. haploid

a. diploid

During DNA replication, the leading strand contains Okazaki fragments. a. false b. true

a. false

In normal meiosis, when do homologous chromosomes separate from each other? a. in the first meiotic division b. They may separate in either the first or second meiotic divisions. c. in the second meiotic division

a. in the first meiotic division

In humans, the rate of point mutation tends to be greater in males than in females because: a. male germ-line cells undergo many more divisions than female germ-line cells. b. the testes are more exposed to the environment than the ovaries. c. DNA repair in males is less efficient than that in females. d. male meiosis is more sensitive to mutagens than female meiosis

a. male germ-line cells undergo many more divisions than female germ-line cells.

Nondisjunction in ______________ results in offspring inheriting the mutation. a. meiosis b. mitosis

a. meiosis

In animals with sex chromosomes, males inherit their Xchromosome from their ___ and transmit it to their___. a. mothers; daughters b. mothers; sons and daughters c. mothers; sons d. fathers; daughters

a. mothers; daughters

An allele is: a. one of several forms of a gene. b. the location of a gene in a chromosome. c. the expression of a trait in an individual. d. the particular combination of genes for a given trait in a given organism. e. None of the other answer options is correct.

a. one of several forms of a gene.

What is the process of "proofreading" by DNA polymerase? a. removing an improperly paired base and replacing it with the proper one b. re-replicating a template of DNA for a second time c. changing the DNA sequence to produce improved protein structures d. removing introns from the sequence and joining exons to each other

a. removing an improperly paired base and replacing it with the proper one

Recall from the text that there are four clusters of Y-chromosome haplotypes scattered across the globe. Where would you expect to find these clusters? a. the Americas; Southeast Asia; Europe; Africa b. the Americas; Australia; Iceland; Australia c. North America; South America; China; Eastern Europe d. India; Africa; the Middle East; Antarctica e. North America; Southern Africa; Eastern Europe; India

a. the Americas; Southeast Asia; Europe; Africa Clusters of related haplotypes are more likely to be found within a specific geographic region, and not between geographic regions.

On which strand are new nucleotides being added in the same direction as the replication fork is opening? a. the leading strand b. the lagging strand c. On both strands, DNA synthesis is proceeding in the same direction as the replication fork.

a. the leading strand

In Mendel's crosses: a. the plants he started with had two alleles of each gene. b. the F1 plants had a 3:1 ratio of yellow to green. c. the plants he started with were heterozygous.

a. the plants he started with had two alleles of each gene.

What is the first thing to occur in DNA replication? a. the strands of the DNA double helix are separated b. the extension of DNA from the 3′ end of the RNA primer c. the synthesis of a short RNA primer d. the removal of the RNA primer, which is replaced by DNA

a. the strands of the DNA double helix are separated

In humans, fruit flies, and many other organisms, most of the genes on the X chromosome are not found on the Y chromosome. a. true b. false

a. true

Synthesis of nucleic acids always occurs in the 5′ → 3′ direction. a. true b. false

a. true

Recessive alleles in the X chromosome are expressed in males because: a.the Y chromosome does not contain the wild-type allele. b. the X chromosome is dominant in males. c. males are more sensitive to mutations than females. d. All of these choices are correct.

a.the Y chromosome does not contain the wild-type allele.

How did Mendel make crosses with his plants? a. He cut the peas in half and combined them to grow a single plant. b. He grew plants from seeds and fertilized the ovules of one plant with the pollen from another. c. He allowed the pea plants to intertwine during growth to allow fertilization. d. He planted the seeds of each type together, and they grew into a single plant.

b. He grew plants from seeds and fertilized the ovules of one plant with the pollen from another.

In Jabberwocks, flame eyes (F) are dominant to blue eyes (f) and burbling (B) is dominant to whistling (b). Jabberwock geneticists suspect that the two genes are linked in one of the autosomes. They mate a true-breeding, flame-eyed, burbling female with a true-breeding, blue-eyed, whistling male. They then mate a pair of the offspring. If the genes are linked, which of the F2 genotypes will be rarer than would be expected if the genes were not linked? Select all that apply. a. FF BB b. FF bb c. FF bb d. ff BB e. ff bb

b. FF bb c. FF bb d. ff BB

Darwin believed in the theory of blending inheritance. a. True b. False

b. False

During meiosis, two rounds of DNA synthesis are required to form four gametes from one parent cell. a. True b. False

b. False

In a male fruit fly, the white-eye gene is carried in the Y chromosome: a. True b. False

b. False

For a single-gene trait with alleles A and a, which offspring are expected from the mating AA × aa? a. 1/4 AA : 1/2 Aa : 1/4 aa b. None of the other answer options are correct. c. 1/2 AA : 1/2 Aa d. 1/2 AA : 1/2 aa e. 1/2 Aa : 1/2 aa

b. None of the other answer options are correct. The mating AA × aa produces only Aa offspring.

Cytokinesis usually, but not always follows mitosis. If a eukaryotic cell completed mitosis but not cytokinesis, what would one see under the microscope? a. 2 cells with one nuclei in each b. One cell with two nuclei c. 4 cells with one nuclei in each

b. One cell with two nuclei

When Mendel crossed yellow peas with green peas, the next generation was all yellow. How is this explained? a. The offspring didn't get enough sunlight and so turned yellow. b. The parental plants pass one of their two alleles on to the offspring which is heterozygous, and the A allele is dominant to the a allele. c. Mendel used the pollen from the yellow plant in the cross, and the pollen is what determines the trait in the offspring.

b. The parental plants pass one of their two alleles on to the offspring which is heterozygous, and the A allele is dominant to the a allele.

Which of the following is most likely to result in a nonfunctional polypeptide (protein)? a. a missense mutation b. a nonsense mutation c. a transition mutation d. a silent mutation

b. a nonsense mutation

Segregation of alleles corresponds to the separation of: a. genotypes. b. chromosomes. c. genes. d. phenotypes.

b. chromosomes.

A wild-type fruit fly: a. exhibits a mutant phenotype. b. exhibits the most common phenotype in the population. c. exhibits a phenotype that marks it as a party animal. d. will most likely have white eyes.

b. exhibits the most common phenotype in the population.

The semiconservative model of DNA replication means that each DNA strand of the double helix consists of some newly synthesized DNA and some parental DNA. a. true b. false

b. false

If nondisjunction occurs in the first meiotic division, how many of the four possible gametes produced from meiosis will have the wrong number of chromosomes? a. two b. four c. one d. three

b. four

How would the time required for replication be affected if replication of such a molecule were unidirectional rather than bidirectional in bacteria? a. decrease b. increase

b. increase

Homologous pairs of chromosomes separate during: a. meiosis II and mitosis. b. meiosis I. c. meiosis II. d. mitosis. e. meiosis I and mitosis.

b. meiosis I.

Y-linked traits are: Select all that apply. a. transmitted by carrier females. b. never inherited by females. c. transmitted by affected fathers to their sons. d. transmitted by affected fathers to their daughters. e. never transmitted by females.

b. never inherited by females. c. transmitted by affected fathers to their sons. e. never transmitted by females.

Sometimes homologous chromosomes fail to separate normally during meiosis I, a process called: a.nontransference. b. nondisjunction. c. chromosome separation. d. conjugation. e. unijunction.

b. nondisjunction.

Reproduction by mitotic cell division: a. involves the formation of gametes. b. results in two daughter cells that are genetically identical. c. does not require the replication of chromosomes. d. reduces the number of chromosomes by half.

b. results in two daughter cells that are genetically identical.

Okazaki fragments are found on _____ strand of DNA. a. the leading b. the lagging c. both the leading and lagging d. the parental

b. the lagging

On which strand is DNA synthesis discontinuous, occurring in fragments that are later connected? a. the leading strand. b. the lagging strand c. Both strands synthesize DNA in fragments.

b. the lagging strand

The principle of independent assortment holds that: a. during fertilization, haploid gametes join to create a diploid zygote. b. the pattern of inheritance of one trait does not influence the pattern of inheritance of another trait. c. in heterozygotes, half the gametes will get one allele, and the other half will get the second allele. d. in heterozygotes, the phenotype will be determined by the dominant allele.

b. the pattern of inheritance of one trait does not influence the pattern of inheritance of another trait.

An individual is homozygous for a gene if: a. they developed from a sperm and an egg that carried different alleles. b. they developed from a sperm and an egg that carried the same allele. c. the mother is homozygous for the gene. d. the father is homozygous for the gene. e. None of the other answer options is correct.

b. they developed from a sperm and an egg that carried the same allele.

Alleles are alternate molecular forms of a gene. a. false b. true

b. true

Any mutation that has no effect on the organism is considered neutral. a. false b. true

b. true

Color blindness is a recessive X-linked trait in humans. In a family where the mother is color-blind and the father is normal, the probability of their having a color-blind son is: a. 0. b. 1/4. c. 1. d. 1/16. e. 1/2.

c. 1.

For most genes on the human X chromosome, what percent of XY males with a mutant allele on the X chromosome will express the mutant phenotype? a. 50% b. 0% c. 100% d. 25% e. There is insufficient data to predict.

c. 100%

The leading strand is the daughter strand that has its ____ end pointed toward the replication fork and is therefore synthesized ______. a. 3′; in a series of segments b. 5′; in a series of segments c. 3′; continuously d. 5′; continuously

c. 3′; continuously

Which of the strands use a template for DNA replication? a. the leading strand b. the lagging strand c. Both strands use a template during DNA replication

c. Both strands use a template during DNA replication

In his cross, what did Mendel do? a. He did not use pure-breeding plants in his crosses. b. He used plants that were heterozygous in his initial crosses. c. He studied traits controlled by a single gene.

c. He studied traits controlled by a single gene.

If the concept of blending inheritance were true, would variation increase or decrease over time? a. It would stay the same. b. It would increase. c. It would decrease.

c. It would decrease.

Which mutations in an animal somatic cell would be inherited by the next generation of offspring? a. deletions b. synonymous mutations c. None of the other answer options is correct d. point mutations

c. None of the other answer options is correct

In which type of nondisjunction could the two copies of a chromosome in a gamete be heterozygous? a. nondisjunction in the second meiotic division b. Nondisjunction in either meiotic division could produce gametes with two copies of a chromosome that are heterozygous. c. nondisjunction in the first meiotic division

c. nondisjunction in the first meiotic division

Reproduction by mitotic cell division: a. does not require the replication of chromosomes. b. involves the formation of gametes. c. results in two daughter cells that are genetically identical. d. reduces the number of chromosomes by half.

c. results in two daughter cells that are genetically identical.

Mendel's principle of segregation corresponds to what part of meiosis? a. alignment of homologs in metaphase I b. condensation of chromosomes in prophase I c. separation of homologs in anaphase I d. alignment of chromosomes in metaphase II

c. separation of homologs in anaphase I

Morgan's discovery of a white-eyed male was important because the mutant gene proved to be in: a. the Y chromosome. b. an autosome. c. the X chromosome. d. the mitochondrial DNA.

c. the X chromosome.

What is the function of the enzyme DNA polymerase? a. to synthesize a strand of DNA using a polypeptide as a template b. to synthesize a polypeptide using DNA as a template c. to synthesize a strand of DNA using DNA as a template d. to synthesize a strand of mRNA using DNA as a template e. to synthesize a strand of mRNA using mRNA as a template

c. to synthesize a strand of DNA using DNA as a template

In a cross between two individuals who are heterozygous for two traits determined by dominant and recessive alleles (Aa Bb), what is the expected ratio of offspring for the trait determined by the first gene (Aa)? a. 12:4:4:1 b. 1:1 c. 9:3:3:1 d. 3:1

d. 3:1

You decide to compare the genes and DNA sequence of a specific chromosome to a homologous chromosome and a nonhomologous chromosome. Which of the predictions would you make when comparing the two? a. The homologous chromosome will have the same genes and an identical DNA sequence. b. The nonhomologous chromosome will have the same genes but in a different order. c. The nonhomologous chromosome will have different genes but a similar DNA sequence. d. The homologous chromosome will have the same genes and a similar DNA sequence. e. The homologous chromosome will have the same genes but in a different order.

d. The homologous chromosome will have the same genes and a similar DNA sequence.

Which of the following is likely not to affect the protein function? a. a nonsense mutation b. a missense mutation c. a transition mutation d. a silent mutation

d. a silent mutation

What is nondisjunction? a. failure of chromosomal replication b. failure of chromosomal condensation c. failure of chromosomal pairing d. failure of chromosomal separation

d. failure of chromosomal separation

In genetic crosses, the symbol Aa refers to a: a. holotype. b. phenotype. c. archetype. d. genotype. e. morphotype.

d. genotype.

If you crossed a true-breeding yellow-seed plant (AA) with a heterozygous yellow-seed plant (Aa), offspring: a. genotypes would be 1 Aa:1 aa. b. genotypes would be 1 AA:2 Aa. c. phenotypes would be 1/2 yellow-seed plants and 1/2 green-seed plants. d. genotypes would be 1 AA:1 Aa. Use a Punnett square to determine that the homozygous parent would produce only gametes with the dominant allele, and the heterozygous plant would produce gametes with either the dominant or recessive allele. Those gametes could combine to pro-duce either homozygous dominant or heterozygous progeny.

d. genotypes would be 1 AA:1 Aa. Use a Punnett square to determine that the homozygous parent would produce only gametes with the dominant allele, and the heterozygous plant would produce gametes with either the dominant or recessive allele. Those gametes could combine to pro-duce either homozygous dominant or heterozygous progeny.

Mendel crossed true-breeding yellow-seed plants with true-breeding green-seed plants. Given that yellow color is a dominant trait, what would the genotype of the offspring be? a. a mixture of yellow and green seed b. yellow seed c. green seed d. heterozygous for yellow and green alleles

d. heterozygous for yellow and green alleles

In genetic crosses, the symbols AA and Aa refer respectively to: a. homozygous and heterozygous morphotypes. b. heterozygous and homozygous phenotypes. c. homozygous and heterozygous phenotypes. d. homozygous and heterozygous genotypes. e. heterozygous and homozygous genotypes.

d. homozygous and heterozygous genotypes.

A testcross involves crossing with a(n) _____ individual and is used to determine the _____ of the tested parent. a. F2 offspring; parental genotype b. homozygous dominant; phenotype c. homozygous dominant; genotype d. homozygous recessive; genotype e. homozygous recessive; phenotype

d. homozygous recessive; genotype

During which phase of meiosis do homologous chromosomes synapse with crossing-over between homologous chromosomes? a. both prophase I and prophase II b. neither prophase I nor prophase II c. prophase II d. prophase I

d. prophase I

Mendel's principle of segregation corresponds to what part of meiosis? a. telophase b. alignment of homologs in metaphase I c. alignment of chromosomes in metaphase II d. separation of homologs in anaphase I e. condensation of chromosomes in prophase I

d. separation of homologs in anaphase I

A phenotype is: a. None of the other answer options is correct. b. the location of a gene in a chromosome. c. the particular combination of alleles present in a given organism. d. the expression of a trait in an individual. e. one of several forms of a gene.

d. the expression of a trait in an individual.

If an individual is homozygous for a certain allele, it means that: a. None of the other answer options is correct. b. the allele is neutral. c. the allele is rare in the population. d. the individual received the same allele from each parent. e. the allele is beneficial.

d. the individual received the same allele from each parent.

A genotype is: a. None of the other answer options is correct. b. the expression of a trait in an individual. c. the location of a gene in a chromosome. d. the particular combination of alleles present in a given organism. e. one of several forms of a gene.

d. the particular combination of alleles present in a given organism.

How frequently is an improper base incorporated into the growing daughter strand? a. about half the time b. each time there is a purine rather than a pyrimidine on the template strand c. frequently d. very rarely

d. very rarely

When Mendel crossed true-breeding dominant yellow-seed plants with true-breeding recessive green-seed plants, the offspring were phenotypically: a. green-seed plants. b. a mixture of yellow- and green-seed plants. c. made up of a combination of yellow and green alleles. d. yellow-seed plants.

d. yellow-seed plants.

Suppose that in humans the ability to roll the tongue (R) is dominant to being unable to roll it (r), and having freckles (F) is dominant to having no freckles (f). If a woman heterozygous for both traits married a man with no freckles who couldn't roll his tongue, what is the probability that they would have a freckled, tongue-rolling child? a. 3/4 b. 3/16 c. 1/16 d. 9/16 e. 1/4

e. 1/4 The chance the child has both traits is the chance the child inherits the dominant allele of each from their mother. Inheriting the dominant allele of R (1/2) AND the dominant allele of F (1/2) = 1/2 × 1/2 = 1/4.

Which of the following is not true of mitotic cell division? a. It occurs in eukaryotes, but not in prokaryotes. b. It is a highly regulated process. c. It is a form of asexual reproduction. d. It is a process that is very important in the life cycle of sexually reproducing organisms. e. It does not require DNA replication.

e. It does not require DNA replication.

In a homozygous genotype: a. the individual will be phenotypically dominant. b. the two alleles for a given trait are different. c. both alleles for a given trait are the same, and the individual will be phenotypically dominant. d. the individual will be phenotypically recessive. e. both alleles for a given trait are the same.

e. both alleles for a given trait are the same.

A normal female who carries a recessive X-linked allele for hemophilia will pass it on to: a. half of her sons. b. all of her daughters. c. half of her daughters. d. all of her sons. e. half of both her sons and daughters.

e. half of both her sons and daughters.

An organism that has two different alleles of a given gene has a(n) _____ genotype. a. dizygous b. homozygous c. aneuploid d. heteromorphic e. heterozygous

e. heterozygous

A point mutation that causes an amino acid replacement is called a: a. transition mutation. b. nonsense mutation. c. stop mutation. d. synonymous (silent) mutation. e. nonsynonymous (missense) mutation.

e. nonsynonymous (missense) mutation.

Failure of cell division in anaphase I in meiosis can result in a: a. haploid gamete and diploid gamete. b. diploid fertilized egg c. haploid gamete. d. diploid gamete. e. triploid fertilized egg and diploid gamete.t! f. triploid fertilized egg.

e. triploid fertilized egg and diploid gamete.

In Mendel's pea plants, each cell in a pea plant had a total of: a. one allele for each gene if it had green seeds and two if it had yellow seeds. b. between one and four alleles for each gene. c. one allele for each gene. d. one allele for each gene if it was a true-breeding parent and two if it was an F1 offspring. e. two alleles for each gene.

e. two alleles for each gene.