Question 1

In humans,hemophilia is caused by a recessive allele on the X chromosome.Suppose a man with hemophilia has children with a healthy woman whose mother had hemophilia.What is the probability that their second child will have hemophilia? (Enter the probability as a percent.Enter the number only without the percent sign.For example,enter 100% as 100 and enter 12.5% as 12.5)

Accepted Answer

The answer of In humans,hemophilia is caused by a recessive...

Question 2

Traits that are controlled by genes located on the X chromosome are said to be ________.

Accepted Answer

A)  autosomal
B)  gametal
C)  sex-linked
D)  pleiotropicE) B) and C)
F) C) and D)

Question 3

In humans,if an XY individual had a deletion of the SYR gene,that person would

Accepted Answer

A)  develop as a female.
B)  have both male and female characteristics.
C)  have ambiguous genitalia.
D)  develop as a male.E) None of the above
F) All of the above

Question 4

In sickle cell anemia,the defective hemoglobin differs from the normal hemoglobin by

Accepted Answer

A)  the color of the pigment.
B)  the size of the molecule.
C)  a single amino acid substitution.
D)  the total number of amino acids.
E)  the type of blood cell it is found in.F) A) and B)
G) B) and C)

Question 5

Which offspring inherit all their mitochondrial DNA from their mother and none from their father?

Accepted Answer

A)  daughters
B)  sons
C)  both sons and daughters
D)  neither sons nor daughtersE) C) and D)
F) A) and B)

Question 6

The most common fatal genetic disorder of Caucasians is

Accepted Answer

A)  cholera.
B)  cystic fibrosis.
C)  hemophilia.
D)  sickle cell anemia.
E)  muscular dystrophy.F) A) and E)
G) B) and C)

Question 7

In humans,if nondisjunction led to an individual with a genotype of XXY,that person would

Accepted Answer

A)  be female because each cell has two X chromosomes.
B)  be male because each cell has one Y chromosome.
C)  display both male and female characteristics.
D)  not survive.E) None of the above
F) A) and C)

Question 8

Genetic maps are based on recombination frequencies.Because both odd and even numbers of crossovers can occur between any two gene loci,as the physical distance between two loci increases,the maximum recombination frequency levels off at 50%.However,suppose you discovered a species where only an even number of crossovers can occur between any two gene loci.In this case,as the physical distance between two loci increases,you would expect the maximum recombination frequency to

Accepted Answer

A)  remain at zero.
B)  increase with no limit.
C)  level off at 25%.
D)  level off at 75%.
E)  level off at 100%.F) All of the above
G) A) and B)

Question 9

In humans,individuals with trisomy of the ________ chromosome are most likely to survive until adulthood.

Accepted Answer

A)  3rd.
B)  13th.
C)  15th.
D)  18th.
E)  21st.F) A) and B)
G) A) and C)

Question 10

A deletion of a particular stretch of chromosome 15 can cause either Prader-Willi syndrome or Angelman syndrome,depending on

Accepted Answer

A)  the parental origin of the normal and deleted chromosome.
B)  whether or not the region is methylated properly.
C)  whether a translocation event has occurred.
D)  whether a nondisjunction event has occurred.E) All of the above
F) None of the above

Question 11

In fruit flies (Drosophila melanogaster)there is a dominant allele for red eyes and a recessive allele for white eyes.These alleles are located on the X chromosome.If a heterozygous red-eyed female is mated with a white-eyed male,what percentage of the offspring are expected to be white-eyed females? (Enter the number only without the percent sign.For example,enter 100% as 100 and enter 12.5% as 12.5)

Accepted Answer

The answer of In fruit flies (Drosophila melanogaster)there is a...

Question 12

In some human populations,the proportion of individuals who are heterozygous for the sickle cell allele is much higher than would be expected by chance alone.Why?

Accepted Answer

A)  Individuals with two normal alleles have an advantage over heterozygous individuals.
B)  Individuals with two harmful alleles have an advantage over heterozygous individuals.
C)  Individuals with two harmful alleles have an advantage over individuals with two normal alleles.
D)  Heterozygous individuals have an advantage over individuals with two normal alleles.E) A) and C)
F) C) and D)

Question 13

If a human female has 2 Barr bodies per cell,it is almost certain that

Accepted Answer

A)  her father had 1 Barr body per cell.
B)  her mother also had 2 Barr bodies per cell.
C)  she developed from a fertilized egg with 3 X chromosomes.
D)  she is genetically a male with female characteristics.
E)  she is genetically a normal fertile female.F) B) and E)
G) A) and E)

Question 14

Huntington's disease is caused by a single dominant allele.It is a lethal disease,yet it persists in the human population.Which of the following statements best describes why?

Accepted Answer

A)  Huntington's disease is sex-linked and every human has at least one X chromosome; thus,the chances are extremely high for this allele to be maintained in the human population.
B)  Huntington's disease can present symptoms so mild that they appear to lack dominant expression of the allele in some individuals; in those cases,the allele is passed on to the offspring.
C)  While lethal to a parent,Huntington's disease will not be lethal to the offspring since it can skip a generation.
D)  Huntington's disease presents symptoms in mid-life,after most people have already had offspring.
E)  Even though Huntington's disease is lethal,it improves chances for reproduction before the person dies.F) A) and E)
G) A) and D)

Question 15

In Drosophila,the allele red eyes (bw+) is dominant to the allele for brown eyes (bw) .At another gene locus on the same chromosome,the allele for thin wing veins (hv+) is dominant to the allele for heavy wing veins (hv) .Flies homozygous for bw and hv+ are crossed to flies homozygous for bw+ and hv to obtain doubly heterozygous F1 progeny.
-Given that these two gene loci are very closely linked,the phenotypic ratio in the F2 generation should be closest to

Accepted Answer

A)  1 brown eye,heavy wing veins: 2 red eye,thin wing veins: 1 brown eye,thin wing veins
B)  1 brown eye,thin wing veins: 2 red eye,thin wing veins: 1 red eye,heavy wing veins
C)  3 red eye,thin wing veins: 1 brown eye,heavy wing veins
D)  1 brown eye: 1 red eye: 1 heavy wing veins: 1 thin wing veinsE) A) and C)
F) A) and D)

Question 16

How did the development of anonymous markers aid in the production of a human genetic map?

Accepted Answer

A)  Anonymous markers are genetic markers that do not cause a detectable phenotype,but can be detected by molecular techniques.The markers correspond to specific and unique chromosomal regions,thereby allowing for the identification and ordering of particular segments of DNA.Such information was essential to the generation of a human genetic map.
B)  Anonymous markers are genetic markers that cause a detectable phenotype and can't be detected by molecular techniques.The markers correspond to specific and unique chromosomal regions,thereby allowing for the identification and ordering of particular segments of DNA.Such information was essential to the generation of a human genetic map.
C)  Anonymous markers are genetic markers that do not cause a detectable phenotype,but can be detected by molecular techniques.The markers correspond to specific and unique genetic regions,thereby allowing for the identification and ordering of particular segments of the chromosome.Such information was essential to the generation of a human genetic map.D) A) and B)
E) A) and C)

Question 17

Nondisjunction of a single pair of autosomes can lead to all of the following except

Accepted Answer

A)  aneuploidy.
B)  monosomy.
C)  trisomy.
D)  euploidy.E) B) and C)
F) C) and D)

Question 18

The geneticist who discovered the white eye mutation in Drosophila and helped establish that genes are carried on chromosomes was

Accepted Answer

A)  Mendel.
B)  Sutton.
C)  Sturtevant.
D)  Janssens.
E)  Morgan.F) A) and B)
G) A) and C)

Question 19

Why isn't mitochondrial DNA a unique identifier?

Accepted Answer

A)  Mitochondrial DNA is inherited through the paternal lineage.All offspring inherit their father's mitochondria,and therefore the same mitochondrial DNA.As a result,all family members that share a paternal lineage would have the same mitochondrial DNA.Mitochondrial DNA can therefore be used to confirm or eliminate a person's relationship within a paternal line,but cannot be used to identify a specific individual.
B)  Mitochondrial DNA is inherited through the maternal lineage.All offspring inherit their mother's mitochondria,and therefore the same mitochondrial DNA.As a result,all family members that share a maternal lineage would have the same mitochondrial DNA.Mitochondrial DNA can therefore be used to confirm or eliminate a person's relationship within a maternal line,but cannot be used to identify a specific individual.
C)  Mitochondrial DNA is inherited through the maternal lineage.All female offspring inherit their mother's mitochondria,and therefore the same mitochondrial DNA.As a result,all female family members that share a maternal lineage would have the same mitochondrial DNA.Mitochondrial DNA can therefore be used to confirm or eliminate a person's relationship within a maternal line,but cannot be used to identify a specific individual.D) A) and B)
E) None of the above

Question 20

In Drosophila,the allele red eyes (bw+) is dominant to the allele for brown eyes (bw) .At another gene locus on the same chromosome,the allele for thin wing veins (hv+) is dominant to the allele for heavy wing veins (hv) .Flies homozygous for bw and hv+ are crossed to flies homozygous for bw+ and hv to obtain doubly heterozygous F1 progeny.
-Given that these two gene loci are very closely linked,the genotypic ratio in the F2 generation should be closest to

Accepted Answer

A)  1:2:1
B)  1:1:1:1
C)  9:3:3:1
D)  3:1E) None of the above
F) A) and B)

Exam 13: Chromosomes, mapping, and the Meiosisinheritance Connection

How did the development of anonymous markers aid in the production of a human genetic map?

Correct Answer
verified

The most common fatal genetic disorder of Caucasians is

Correct Answer
verified

Traits that are controlled by genes located on the X chromosome are said to be ________.

Correct Answer
verified

Correct Answer
verified

Nondisjunction of a single pair of autosomes can lead to all of the following except

Correct Answer
verified

The geneticist who discovered the white eye mutation in Drosophila and helped establish that genes are carried on chromosomes was

Correct Answer
verified

In humans,if nondisjunction led to an individual with a genotype of XXY,that person would

Correct Answer
verified

Why isn't mitochondrial DNA a unique identifier?

Correct Answer
verified

Correct Answer
verified

Which offspring inherit all their mitochondrial DNA from their mother and none from their father?

Correct Answer
verified

Correct Answer
verified

A deletion of a particular stretch of chromosome 15 can cause either Prader-Willi syndrome or Angelman syndrome,depending on

Correct Answer
verified

Huntington's disease is caused by a single dominant allele.It is a lethal disease,yet it persists in the human population.Which of the following statements best describes why?

Correct Answer
verified

If a human female has 2 Barr bodies per cell,it is almost certain that

Correct Answer
verified

In some human populations,the proportion of individuals who are heterozygous for the sickle cell allele is much higher than would be expected by chance alone.Why?

Correct Answer
verified

Correct Answer
verified

In humans,individuals with trisomy of the ________ chromosome are most likely to survive until adulthood.

Correct Answer
verified

Correct Answer
verified

In sickle cell anemia,the defective hemoglobin differs from the normal hemoglobin by

Correct Answer
verified

In humans,if an XY individual had a deletion of the SYR gene,that person would

Correct Answer
verified

Exam 13: Chromosomes, mapping, and the Meiosisinheritance Connection

How did the development of anonymous markers aid in the production of a human genetic map?

Correct AnswerverifiedShow Answer

The most common fatal genetic disorder of Caucasians is

Correct AnswerverifiedShow Answer

Traits that are controlled by genes located on the X chromosome are said to be ________.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Nondisjunction of a single pair of autosomes can lead to all of the following except

Correct AnswerverifiedShow Answer

The geneticist who discovered the white eye mutation in Drosophila and helped establish that genes are carried on chromosomes was

Correct AnswerverifiedShow Answer

In humans,if nondisjunction led to an individual with a genotype of XXY,that person would

Correct AnswerverifiedShow Answer

Why isn't mitochondrial DNA a unique identifier?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which offspring inherit all their mitochondrial DNA from their mother and none from their father?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

A deletion of a particular stretch of chromosome 15 can cause either Prader-Willi syndrome or Angelman syndrome,depending on

Correct AnswerverifiedShow Answer

Huntington's disease is caused by a single dominant allele.It is a lethal disease,yet it persists in the human population.Which of the following statements best describes why?

Correct AnswerverifiedShow Answer

If a human female has 2 Barr bodies per cell,it is almost certain that

Correct AnswerverifiedShow Answer

In some human populations,the proportion of individuals who are heterozygous for the sickle cell allele is much higher than would be expected by chance alone.Why?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

In humans,individuals with trisomy of the ________ chromosome are most likely to survive until adulthood.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

In sickle cell anemia,the defective hemoglobin differs from the normal hemoglobin by

Correct AnswerverifiedShow Answer

In humans,if an XY individual had a deletion of the SYR gene,that person would

Correct AnswerverifiedShow Answer

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