Deck 7: Anatomy and Function of a Gene: Dissection Through Mutation

Question 1

Unequal crossing over results in

A)an exchange between nonhomologous chromosomes.
B)a loss of genetic material.
C)a repair of UV-induced damage.
D)a production of eggs containing Y chromosomes.
E)a creation of deletions and duplications.

Answer 1

a creation of deletions and duplications.

Question 2

Thymine dimers are caused by

A)X-rays.
B)free radicals such as oxygen.
C)EMS or NSG.
D)depurination.
E)UV light.

Answer 2

UV light.

Question 3

Assume that a wild-type sequence is 5'AGCCTAC3'.Indicate the sequence that might be produced by a transversion.

A)5'AGTCTAC3'
B)5'AGCCGCCGCCGCCTAC3'
C)5'AGCCCAC3'
D)5'ATCCTAC3'
E)5'AGCCTGC3'

Answer 3

5'ATCCTAC3'

Question 4

The term mutation refers to

A)only changes in the DNA that result in new phenotypes.
B)only changes in the DNA that result in novel proteins.
C)any change in the DNA of a cell.
D)a heritable change in the DNA of a cell.
E)any change in the cell that changes its survival chances.

Question 5

A heritable change in DNA base sequence is called a

A)forward mutation.
B)reversion.
C)substitution.
D)deletion.
E)mutation

Question 6

The duplication of the triplet sequence CGG resulting in elongation or breakage of the X chromosome is termed

A)Barr-eyed.
B)Huntington's disease.
C)unequal crossing over
D)Fragile X syndrome.
E)Rhys syndrome

Question 7

Which type of mutation is least likely to revert?

A)deletion
B)transition
C)transversion
D)insertion
E)All are equally likely

Question 8

Replacing a thymine nucleotide with a guanine is an example of a

A)translocation.
B)transition.
C)transversion.
D)forward mutation.
E)reversion or reverse mutation

Question 9

If a man shows the premutation allele for Fragile X syndrome, what is the probability that he will pass it on to his son?

A)100%
B)75%
C)50%
D)25%
E)0%

Question 10

Assume that the mutation rate for a given gene is 5*10⁶ mutations per gene per generation.For that gene how many mutations would be expected if 10 million sperm are examined?

A)none
B)5*10⁶
C)5
D)50
E)500

Question 11

A mutation in which parts of two nonhomologous chromosomes change places is called a(n)

A)translocation.
B)transition.
C)transversion.
D)insertion.
E)deletion.

Question 12

In the Luria Delbruck fluctuation experiment, the bacteria + phage plates showed

A)all plates had some resistant colonies, some had very many.
B)some plates had no resistant colonies, a few plates had very many resistant colonies.
C)all plates had the same number of resistant colonies.
D)some plates had no resistant colonies; the plates that had resistant colonies all had the same number of resistant colonies.
E)phage caused mutations to occur in some of the plates but not in others

Question 13

Replacing an adenine nucleotide with a guanine is an example of a

A)translocation.
B)transition.
C)transversion.
D)forward mutation.
E)reversion or reverse mutation

Question 14

The results of the Luria Delbruck fluctuation experiment indicated that

A)bacteria are naturally resistant to phage.
B)a low level of any bacterial population is naturally resistant to phage.
C)bacteria become resistant to phage by mutation when exposed to phage.
D)bacteria become resistant to phage by random spontaneous mutation.
E)the phage mutate to produce large plaques with sharp edges.

Question 15

Assume that a researcher set out to duplicate the Luria Delbruck fluctuation experiment.This researcher planted twenty small flasks with bacteria from the same colony and let them grow overnight.The next morning the researcher noticed that all but one of the flasks had come open and were ruined.Not wishing to redo the experiment the researcher took bacteria samples from the one remaining intact flask and placed them on twenty phage plates.What results would you expect to see when the twenty phage plates are examined, and how would these results compare with those of the original Luria Delbruck fluctuation experiment?

A)Identical to the Luria Delbruck results, namely different numbers of resistant colonies.
B)Identical to the Luria Delbruck results, namely identical numbers of resistant colonies.
C)Not like the Luria Delbruck results, namely different numbers of resistant colonies.
D)Not like the Luria Delbruck results, namely identical numbers of resistant colonies.
E)Identical to the Luria Delbruck results, namely no resistant colonies.

Question 16

Consider the following results.When 50 million sperm were examined for a specific mutation, 100 mutations were found.Indicate the mutation rate for that gene.

A)5*10⁶
B)50*10⁶
C)2*10⁶
D)2*10⁵
E)5*10⁵

Question 17

The heritable disorder Fragile X syndrome, a major cause of mental retardation, is caused by

A)production of enzymes that break the phosphate backbone.
B)UV light.
C)X-rays.
D)presence of an extra X chromosome in the sperm or egg
E)duplication of multiple three-nucleotide repeats.

Question 18

Genes on the X chromosome of mammals and Drosophila are particularly suitable for genetic study because

A)males have only one X and most genes behave as haploids.
B)females have only one X and most genes behave as haploids.
C)the X chromosome is large and many more genes are located there.
D)when present as Barr bodies they are exposed for electron microscopic examination.
E)they behave as diploids in females.

Question 19

The hydrolysis of a purine base from the deoxyribose-phosphate backbone is called

A)depurination.
B)deamination.
C)replica plating.
D)excision repair.
E)deletion.

Question 20

UV light is a mutagen that can cause

A)depurination.
B)deamination.
C)alkylation.
D)thymine dimers
E)oxidation.

Question 21

Assume that in the organism under study the DNA polymerase has an error rate of 1 mistake in every 10⁶ bases copied.However, the overall mutation rate is much lower.This is most likely because

A)the polymerase is more careful in replicating regions where genes exist
B)repair mechanisms correct errors made by the polymerase.
C)not all mutations can be detected easily.
D)the DNA polymerase has no proofreading function
E)mutations do not occur if mutagens are not present

Question 22

Shown below are the deletion maps of a series of rII^- mutations.The deleted region is indicated as (......) and the intact region as ______.Note that strain 5 carries two different deletions.1 ___________(...........)_______________ 2 _________________(...........)_________
3 ()....................)_____________________
4 ________________________(................)
5 _____(..........)________________(.........)
A series of point mutations A E is used in a coinfection experiment.Shown below are the results of those coinfections.Ability to produce wild-type progeny phage is indicated by (+), and (o) indicates no wild-type progeny. Indicate the order that is most consistent with these data.

A)CADBE
B)DEBAC
C)BADCE
D)ABDEC
E)CEADB

Question 23

Alkylating agents such as ethylmethane sulfate (EMS) function as mutagens to

A)promote deletions and insertions.
B)remove amine groups
C)add oxygen free radicals to bases.
D)add ethyl or methyl groups.
E)fit between stacked bases and disrupt replication.

Question 24

The genetic condition Xeroderma pigmentosum, which can lead to skin cancer, results from

A)inability to correct UV induced dimers
B)inability to process phenylalanine.
C)inability to produce functional hemoglobin.
D)inability to correct transitions
E)breaks in the X chromosome

Question 25

A complementation group is a group of mutations

A)that produce the same phenotype.
B)that are in the same gene and complement each other.
C)that are in the same gene and do not complement each other.
D)in two different genes that complement each other.
E)in two different genes that do not complement each other.

Question 26

Shown below are the results of a series of coinfections using T4 rII- strains similar to those employed by Benzer.Each strain contains a different deletion mutation.Ability to produce wild-type progeny phage is indicated by (+), and (o) indicates no wild-type progeny. Indicate the order that is most consistent with these data.

A)CADBE
B)ACBDE
C)BADCE
D)BEDCA
E)CEADB

Question 27

Intercalating agents such as acridine orange function as mutagens to

A)promote transitions.
B)remove amine groups.
C)attach to purines causing distortions
D)add ethyl or methyl groups.
E)fit between stacked bases and disrupt replication.

Question 28

If a base analog such as 5-bromouracil is used as a mutagen, how many generations will be required to mutate the codon for proline (CCC) into the codon for alanine (GCC)?

A)one generation
B)two generations
C)three generations
D)at least two, but perhaps more due to chance
E)it will not occur

Question 29

The Ames test for mutagenicity is useful to identify potential carcinogens because

A)bacteria do not get cancer they can survive lethal carcinogens.
B)mutagens that affect bacterial DNA are likely to cause human mutation.
C)bacteria thrive on substances that could cause cancer in humans.
D)the same genes that cause cancer in humans can be mutated in bacteria.
E)liver enzymes alter the bacteria so they will behave like mammal cells.

Question 30

The consequence to a bacterial cell of a mutation that inactivated the enzyme that methylates the A of the sequence GATC in newly made DNA would be

A)failure to carry out replication
B)failure to correct thymine dimers.
C)failure to distinguish old and new DNA during mismatch repair.
D)inactivation of certain metabolic genes.
E)decrease in the mutation rate

Question 31

Excision repair corrects DNA by

A)removing a double-stranded fragment of damaged DNA.
B)detecting, removing, and replacing damaged or incorrect nucleotides in a single strand of DNA.
C)excising the incorrect base from a nucleotide
D)removing extraneous groups such as methyl or oxygen added by mutagens.
E)correcting A=T to C=G transitions.

Question 32

A plaque is

A)a colony of bacteria growing on a plate.
B)a colony of bacteria that contain phage within them.
C)a region on a plate where living bacteria survive phage infection.
D)an area on a plate containing live phage-resistant bacteria.
E)an area on a plate containing phage and dead or destroyed bacteria.

Question 33

Indicate which of the following is least important in doing a complementation test with coinfection of phage T4.

A)ensuring that sufficient phage of both strains are present
B)recovering phage from the plaques after growth and lysis
C)counting the plaques that are produced on
D)control using both mutations in cis configuration and a wild type
E)coli K( $\lambda$ )

Question 34

In the Ames test for mutagenicity

A)auxotrophic bacteria are converted to prototrophs that survive.
B)prototrophic bacteria are converted to auxotrophs that survive.
C)cells are treated with mutagen and only those with no mutations survive
D)cells are treated with excess amino acids, killing cells that carry mutations.
E)rat liver enzymes protect cells from mutation

Question 35

How many progeny phage are released when a single E.coli cell is lysed by phage T4?

A) between 1 and 10
B) between 10 and 100
C) between 100 and 1,000
D) about 10,000
E) about 100,000

Question 36

The bacterial repair system that corrects mismatched bases after polymerization is able to discriminate between the old and newly made DNA strands because

A)the new strand will contain the incorrect base if a mismatch occurs.
B)older DNA is more likely to contain errors.
C)older DNA contains methyl groups at specific sequences
D)newer DNA contains methyl groups at specific sequences
E)the DNA polymerase is attached to the new strand

Question 37

Choose the statement that best distinguishes a complementation test and a recombination analysis when examining mutations in phage.

A)Both tests require two different mutations.
B)Recombination can only occur between two genes.
C)Complementation results can be seen immediately, recombination requires a second infection.
D)Recombination results can be seen immediately, complementation requires a second infection.
E)Recombination can distinguish one gene with two alleles from two different genes.

Question 38

Indicate the correct order for one round of infection by bacteriophage T4.1) Lysis of host cell.2) Phage proteins and DNA synthesized, host DNA degraded.3) Assembly of phage within host cell.4) Phage body enters host cell.5) Phage injects DNA into host cell.

A)4, 2, 3, 1
B)1, 2, 3, 4, 5
C)5, 1, 2, 3,
D)5, 2, 3, 1
E)4, 5, 3, 1

Question 39

Base analogs differ from other classes of mutagen in that they

A)only alter bases
B)can only cause transversions
C)only work during DNA replication or repair.
D)can only cause forward mutations, nor reversions.
E)will not function in bacterial cells.

Question 40

Shown below are the deletion maps of a series of rII- mutations.The deleted region is indicated as (......) and the intact region as ______ 1 ___________(...........)_______________
2 _________________(...........)_________
3 ()....................)_______________ ______
4 ________________________(................)
5 _____(..........)______________________
A series of point mutations A E is used in a coinfection experiment.Shown below are the results of those coinfections.Ability to produce wild-type progeny phage is indicated by (+), and (o) indicates no wild-type progeny. Indicate the order that is most consistent with these data.

A)CADBE
B)DEBAC
C)BADCE
D)ABDEC
E)CEADB

Question 41

Indicate the false statement regarding amino acids.

A)Every amino acid contains a carboxyl group.
B)The side chain or R group differs for each amino acid.
C)Amino acids are joined together by peptide bonds.
D)The end of the polypeptide termed the N terminus contains a free amino group.
E)All the choices are correct.

Question 42

Assume that a transition mutation results in an amino acid substitution in the resulting polypeptide.What level of protein structure might be affected as a result?

A)primary structure
B)secondary structure
C)tertiary structure
D)quaternary structure
E)All levels might be affected by a single amino acid substitution

Question 43

Consider the pathway for the synthesis of the amino acid arginine in Neurospora: Mutant strains of Neurospora are grown in minimal media supplements as follows.The strains may carry more than one mutation.Growth is shown by (+) and no growth is shown by (o). Strain a accumulates citrulline, strain b does not.Indicate the statement that is most correct regarding these two strains.

A)Strain a has a mutation in ARG-E only.
B)Strain b has only one mutation.
C)Strain a has mutations in ARG-F and ARG-H.
D)Strain a has mutations in ARG-E, ARG-F and ARG-H.
E)Strain a has a mutation in ARG-H only.

Question 44

Assume that a series of compounds has been discovered in Neurospora.Compounds A-F appear to be members of an enzyme pathway.Several mutations have been identified and each of strains 1-4 contains a single mutation.Shown below are five possible pathways.Choose the pathway that best fits the data presented.[Growth in minimal media with supplements is shown by (+), no growth is shown by (o)] media supplement

A)A $\rarr$ B $\rarr$ C $\rarr$ D $\rarr$ E $\rarr$ F
B)A $\rarr$ B $\rarr$ C $\rarr$ F $\rarr$ D $\rarr$ E
C)F $\rarr$ B $\rarr$ C $\rarr$ D $\rarr$ A $\rarr$ E
D)A $\rarr$ B $\rarr$ C $\rarr$ D $\rarr$ F $\rarr$ E
E)A $\rarr$ B $\rarr$ F $\rarr$ E $\rarr$ C $\rarr$ D

Question 45

Choose the statement that is most accurate concerning biochemical pathways.

A)All enzymes in the pathway catalyze the same reaction.
B)If an enzyme in a pathway is inactive, adding excessive amounts of its substrate will restore the normal phenotype.
C)If an enzyme in a pathway is inactive, adding excessive amounts of its product will restore the normal phenotype.
D)If the enzyme that catalyzes the final step in a pathway is inactive all the other enzymes will be inactivated as well.
E)If the first enzyme in a pathway is inactivated, adding the final product will not restore the normal phenotype.

Question 46

Examination of the rhodopsin gene family provides evidence for gene evolution by

A)duplication and divergence.
B)accumulation of random mutations.
C)convergent evolution.
D)spontaneous generation.
E)drift.

Question 47

The photoreceptor protein rhodopsin

A)is found in cone cells and is sensitive to weak light at many wavelengths.
B)is found in rod cells and is sensitive to weak light at many wavelengths.
C)is found in cone cells and is responsible for blue and green color vision.
D)is found in rod cells and is responsible for blue and green color vision.
E)is missing in individuals who exhibit red green colorblindness.

Question 48

Assume eight different strains of fly have been isolated, each shows a recessive white eye trait.Crosses are performed as follows (w) indicates white-eyed progeny, (R) indicates wild-type red eyes. Based on these crosses, how many different genes are present and what strains have mutations in the same gene as does strain A?

A)2, B, E, and H
B)3, B, and C
C)3, B, C, and H
D)3, B, E, and H
E)4, B, and H

Question 49

The structure of a protein that involves the interaction between two distinct polypeptide chains is

A)primary structure.
B)secondary structure.
C)tertiary structure.
D)quaternary structure.
E)both primary and secondary structure.

Question 50

Choose the interaction listed below that is not involved in maintaining tertiary structure in protein molecules.

A)covalent bond
B)hydrogen bond
C)hydrophobic/hydrophilic interactions
D)ionic interactions
E)All of the choices may be involved in maintaining protein tertiary structure.

Question 51

In the human genetic disorder Alkaptonuria, urine turns black because of the presence of homogentisic acid in individuals with the trait.This is due to

A)the presence of large amounts of homogentisic acid in the diet.
B)failure of individuals with Alkaptonuria to manufacture enzymes involved in the synthesis of homogentisic acid.
C)failure of wild-type individuals to manufacture enzymes involved in the synthesis of homogentisic acid.
D)failure of the kidneys to remove homogentisic acid from the urine.
E)failure of individuals with Alkaptonuria to manufacture enzymes involved in the breakdown of homogentisic acid.

Question 52

Choose the condition below that does not involve a defect in an enzyme pathway.

A)Alkaptonuria
B)albinism
C)sickle cell anemia
D)Phenylketonuria (PKU)

Question 53

The condition sickle cell anemia is due to

A)the insertion of an amino acid.
B)the deletion of an amino acid.
C)substitution of an amino acid.
D)failure to synthesize a hemoglobin molecule.
E)unequal recombination resulting in the deletion of the $\beta$ -chain hemoglobin gene.

Question 54

Choose the statement below that is not true regarding sickle cell anemia.

A)Individuals who are heterozygous for the sickle cell allele cannot make hemoglobin.
B)The sickle cell hemoglobin molecule contains an amino acid substitution.
C)The hemoglobin molecules of an individual with sickle cell anemia clump together.
D)The red blood cells of an individual with sickle cell anemia distort and elongate.

Question 55

Assume that a researcher is studying coat color in voles.Three strains of white vole have been isolated: milky, blanc, and weiss.White is a recessive trait in each strain.Homozygous white voles are obtained for each strain.Consider the following crosses: milky * blanc = all white progeny
Milky * weiss = all brown (wild-type vole color)
Blanc * weiss = all brown (wild-type vole color)
The conclusion most consistent with these results is

A)all three strains have mutations in the same gene.
B)all three strains have mutations in different genes.
C)milky and blanc have mutations on the same gene, weiss has a mutation in a different gene.
D)milky and weiss have mutations on the same gene, blanc has a mutation in a different gene.
E)weiss and blanc have mutations on the same gene, milky has a mutation in a different gene.

Question 56

Indicate the false statement regarding amino acids.

A)Several amino acids linked together are termed an oligopeptide.
B)Amino acids are linked by peptide bonds that join two amino groups together.
C)The C terminus of a polypeptide chain contains a free carboxylic acid group.
D)Two amino acids joined together are termed a dipeptide.
E)All the choices are correct.

Question 57

Though sickle cell anemia is frequently lethal for individuals who are homozygous for the sickle cell allele, natural selection seems to have maintained that allele in certain geographic locations.A likely explanation for this observation is

A)the forward mutation rate to sickle cell is much higher in those regions.
B)individuals with sickle cell anemia live longer and have more children.
C)reversion from sickle cell to wild type is prevented in some populations.
D)individuals who are heterozygous for the sickle cell allele are protected from malaria.
E)only certain populations have been tested for the presence of the sickle cell allele.

Question 58

Red green color blindness is more common in males than females because

A)the red pigment gene is on the X chromosome, the green is on an autosome.
B)the green pigment gene is on the X chromosome, the red is on an autosome.
C)the rhodopsin gene is on the X chromosome.
D)both the red and the green pigment genes are on the X chromosome.
E)both the red and the green pigment genes are on an autosome.

Question 59

The structure of a polypeptide that is characterized by a three dimensional shape with a characteristic geometry at local regions maintained by hydrogen bonds is

A)primary structure.
B)secondary structure.
C)tertiary structure.
D)quaternary structure.
E)both tertiary and quaternary structures.

Question 60

Consider the pathway for the synthesis of the amino acid arginine in Neurospora: Mutant strains of Neurospora are grown in minimal media supplements as follows.Strains may carry more than one mutation.Growth is shown by (+) and no growth is shown by (o). Indicate the most accurate statement regarding strain A.

A) There is a mutation in ARG-H, if citrulline accumulates, ARG-F is also defective.
B) There is a mutation in ARG-H, if ornithine accumulates, ARG-F is also defective.
C) There is a mutation in ARG-H, if argininosuccinate accumulates, ARG-F is also defective.
D) There is a mutation in ARG-H, if citrulline accumulates, ARG-E is also defective.
E) There is a mutation in ARG-E, if citrulline accumulates, ARG-F is also defective.