Question 1

Which of the following human genotypes is associated with Klinefelter syndrome?

Accepted Answer

A)   XXY
B)   XYY
C)   XXX
D)   XO
E)   XXF) A) and C)
G) C) and E)

Question 2

An XXY chromosome constitution produces _____ development in humans and _____ development in fruit flies.

Accepted Answer

A)   female; female
B)   male; male
C)   female; male
D)   male; female
E)   male, intersexF) A) and B)
G) B) and E)

Question 3

In which of the following individuals would you expect to find two Barr bodies in their somatic cells?

Accepted Answer

A)   XX
B)   XO
C)   XXY
D)   XXYY
E)   XXXF) A) and C)
G) All of the above

Question 4

What is the expected outcome for a human embryo with the XXXY chromosome constitution?

Accepted Answer

A)   It would likely develop into a female who will not respond to the hormone testosterone.
B)   It would likely develop into a sterile male with reduced testes.
C)   It will always abort early in development before birth.
D)   It would likely develop into a tall female who may be slightly cognitively impaired.
E)   It would likely develop into a fertile man with a completely normal male phenotype.F) A) and E)
G) A) and B)

Question 5

Normal males (XY)  and Klinefelter males (XXY)  both possess only one active X chromosome. Nonetheless, there are clearly phenotypic differences between the two. What is the MOST reasonable explanation as to why such differences exist?

Accepted Answer

A)   The Y chromosome has higher gene expression levels when two X chromosomes are present compared to one X.
B)   The Y chromosome has lower gene expression levels when two X chromosomes are present compared to one X.
C)   Some genes remain active on inactive X chromosomes so XXY males would have higher expression levels for these genes compared to XY males.
D)   XXY males exhibit a higher rate of problems during mitotic divisions than XY males.
E)   XXY males don't have a copy of the SRY gene.F) C) and E)
G) A) and D)

Question 6

A phenotypically normal man marries a phenotypically normal woman whose father was color blind. They have a color-blind daughter with Turner syndrome (XO) . What is the BEST explanation for this result?

Accepted Answer

A)   nondisjunction at meiosis II in the mother
B)   nondisjunction at meiosis I in the mother
C)   nondisjunction at meiosis I or meiosis II in the father
D)   mitotic nondisjunction in the first division of the zygote
E)   two sperm fertilized the same egg simultaneouslyF) A) and B)
G) A) and C)

Question 7

Calvin Bridges crossed white-eyed females to red-eyed males and found rare red-eyed males and white-eyed females in the progeny. Explain how he used the Drosophila sex determination system and nondisjunction to demonstrate that the gene for red/white eye color is on the X chromosome.

Accepted Answer

Calvin Bridges used the Drosophila sex d...

Question 8

Suppose that an apparently female athlete fails a gender test and is not allowed to compete in her event. The gender test is based on examination of cheek cells for the presence of one or more Barr bodies. Later, it is discovered that the athlete has androgen-insensitivity syndrome. Evaluate the decision of the officials to exclude the athlete from athletic competition as a female in light of your knowledge of androgen-insensitivity syndrome. Do you think the athlete should be allowed to compete as a female?

Accepted Answer

Androgen insensitivity syndrome (AIS) is...

Question 9

This boy's parents' X chromosomes can be distinguished by polymorphism (DNA fingerprint) differences. One of his mother's X chromosomes has the polymorphism allele 7 and the other has the allele 14; his father's X has the allele 5. Assuming each parent contributed at least one sex chromosome, what polymorphism combinations are possible in the boy's X chromosomes?

Accepted Answer

The answer of This boy's parents' X chromosomes can be...

Question 10

The Lyon hypothesis helps us to understand which phenomenon in mammals?

Accepted Answer

A)   X-linked inheritance
B)   evolution of the Y chromosome
C)   dosage compensation between males and females
D)   development of male and female secondary sexual characteristics
E)   sex determinationF) A) and D)
G) A) and C)

Question 11

During the evolution of the human Y chromosome, all of the following are assumed to occur EXCEPT:

Accepted Answer

A)   the original chromosome was an autosome that eventually evolved into the Y chromosome.
B)   one of the early events in the evolution of the Y chromosome was the acquisition or evolution of a gene somewhat similar to the current human SRY gene.
C)   many of the genes on the original ancestral chromosome suffered mutations and became inactive during the evolution of the Y chromosome.
D)   many of the genes on the early X chromosome that were responsible for critical cellular functions got moved to the evolving Y chromosome.
E)   several palindromic regions evolved or were acquired and are now present on the Y chromosome.F) A) and D)
G) B) and E)

Question 12

What is the sex chromosome constitution of a male duck-billed platypus?

Accepted Answer

A)   XX
B)   XY
C)   XO
D)   ZZ
E)   XXXXXYYYYYF) A) and B)
G) B) and D)

Question 13

A woman is phenotypically normal, but her father had the sex-linked recessive condition of red-green color blindness. If she has children with a man with normal vision, what is the probability that their first child will have normal vision and their second child will be color blind?

Accepted Answer

A)   1/16
B)   3/8
C)   3/16
D)   3/6
E)   8/27F) C) and D)
G) B) and E)

Question 14

A male has Klinefelter syndrome with the chromosome constitution of XXXY. How many Barr bodies should be found in the nuclei of cells of this individual?

Accepted Answer

A)   0
B)   1
C)   2
D)   3
E)   4F) A) and B)
G) B) and D)

Question 15

Red-green color blindness is an X-linked recessive condition. Juliet has a bit of difficulty passing the red-green color distinction test when she tries to get her driver's license. Her husband is not color blind, and neither is her son, Henry, nor her daughter, Roxanne. Roxanne has a son who is color blind. What is Juliet's genotype for the color-blindness allele? How would you explain her partial color blindness?

Accepted Answer

Red-green color blindness is an X-linked...

Question 16

A eukaryotic diploid cell from an organism with the ZZ-ZW sex determination system has two pairs of autosomes and a pair of sex chromosomes, Z and W, shown here.  Assume A and B are dominant alleles. If this individual were crossed to an individual of genotype Aa Bb, what is the probability of an offspring being a female with an A__B__ genotype?

Accepted Answer

A)   1/8
B)   1/16
C)   9/16
D)   9/32
E)   3/32F) None of the above
G) D) and E)

Question 17

A eukaryotic diploid cell from an organism with the XX-XO sex determination system has two pairs of autosomes and one X chromosome, shown here.  What is the probability of a gamete from this individual that has the following genotype: alleles A and b, chromosome X?

Accepted Answer

A)   1/2
B)   1/4
C)   1/6
D)   1/8
E)   1/16F) All of the above
G) A) and B)

Question 18

In Drosophila, flies that are XXY but have a normal diploid set of autosomes have been found. Such XXY chromosome constitutions have also been found in humans. The sex of such individuals is expected to be:

Accepted Answer

A)   male in both Drosophila and humans.
B)   female in both Drosophila and humans.
C)   male in Drosophila but female in humans.
D)   female in Drosophila but male in humans.
E)   intersexes in Drosophila and males in humans.F) A) and E)
G) C) and E)

Question 19

In which of the following organisms is gender/sex determined by the temperature during embryonic development?

Accepted Answer

A)   humans
B)   mice
C)   fruit flies
D)   many snakes and birds
E)   many turtles and alligatorsF) None of the above
G) C) and D)

Question 20

Women known to be heterozygous or carriers for the sex-linked recessive condition of hemophilia A were studied to determine the time required for their blood to clot. It was found that the time required for their blood to clot varied from individual to individual. The values obtained ranged from normal clotting at one extreme to clinical hemophilia at the other extreme. What is the MOST probable correct explanation for these findings?

Accepted Answer

A)   Some women had only one X chromosome and it is inactive.
B)   Some women had three copies of the X chromosome, which allowed them to make extra amounts of gene products for their X-linked genes.
C)   The women with normal clotting times probably had a mother with hemophilia while those with abnormal clotting times probably had fathers with hemophilia.
D)   Random X inactivation probably results in individuals with different proportions of cells in their bodies expressing the normal allele at the hemophilia locus.
E)   In women with abnormal clotting times, there was probably an interaction between an allele of a gene on the X chromosome and an allele of an autosomal gene that reduced the expression of the X-linked gene.F) A) and C)
G) B) and C)

Exam 4: Sex Determination and Sex-Linked Characteristics

Correct Answer
verified

In which of the following organisms is gender/sex determined by the temperature during embryonic development?

Correct Answer
verified

A phenotypically normal man marries a phenotypically normal woman whose father was color blind. They have a color-blind daughter with Turner syndrome (XO) . What is the BEST explanation for this result?

Correct Answer
verified

During the evolution of the human Y chromosome, all of the following are assumed to occur EXCEPT:

Correct Answer
verified

A woman is phenotypically normal, but her father had the sex-linked recessive condition of red-green color blindness. If she has children with a man with normal vision, what is the probability that their first child will have normal vision and their second child will be color blind?

Correct Answer
verified

A eukaryotic diploid cell from an organism with the XX-XO sex determination system has two pairs of autosomes and one X chromosome, shown here. What is the probability of a gamete from this individual that has the following genotype: alleles A and b, chromosome X?

Correct Answer
verified

Calvin Bridges crossed white-eyed females to red-eyed males and found rare red-eyed males and white-eyed females in the progeny. Explain how he used the Drosophila sex determination system and nondisjunction to demonstrate that the gene for red/white eye color is on the X chromosome.

Correct Answer
Answered by ExamLex AI
Calvin Bridges used the Drosophila sex d...
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What is the sex chromosome constitution of a male duck-billed platypus?

Correct Answer
verified

Correct Answer
Answered by ExamLex AI
Androgen insensitivity syndrome (AIS) is...
View Answer

An XXY chromosome constitution produces _ development in humans and _ development in fruit flies.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

In Drosophila, flies that are XXY but have a normal diploid set of autosomes have been found. Such XXY chromosome constitutions have also been found in humans. The sex of such individuals is expected to be:

Correct Answer
verified

In which of the following individuals would you expect to find two Barr bodies in their somatic cells?

Correct Answer
verified

Which of the following human genotypes is associated with Klinefelter syndrome?

Correct Answer
verified

Normal males (XY) and Klinefelter males (XXY) both possess only one active X chromosome. Nonetheless, there are clearly phenotypic differences between the two. What is the MOST reasonable explanation as to why such differences exist?

Correct Answer
verified

What is the expected outcome for a human embryo with the XXXY chromosome constitution?

Correct Answer
verified

The Lyon hypothesis helps us to understand which phenomenon in mammals?

Correct Answer
verified

A male has Klinefelter syndrome with the chromosome constitution of XXXY. How many Barr bodies should be found in the nuclei of cells of this individual?

Correct Answer
verified

Correct Answer
Answered by ExamLex AI
Red-green color blindness is an X-linked...
View Answer

Exam 4: Sex Determination and Sex-Linked Characteristics

Correct AnswerverifiedShow Answer

In which of the following organisms is gender/sex determined by the temperature during embryonic development?

Correct AnswerverifiedShow Answer

A phenotypically normal man marries a phenotypically normal woman whose father was color blind. They have a color-blind daughter with Turner syndrome (XO) . What is the BEST explanation for this result?

Correct AnswerverifiedShow Answer

During the evolution of the human Y chromosome, all of the following are assumed to occur EXCEPT:

Correct AnswerverifiedShow Answer

A woman is phenotypically normal, but her father had the sex-linked recessive condition of red-green color blindness. If she has children with a man with normal vision, what is the probability that their first child will have normal vision and their second child will be color blind?

Correct AnswerverifiedShow Answer

A eukaryotic diploid cell from an organism with the XX-XO sex determination system has two pairs of autosomes and one X chromosome, shown here. What is the probability of a gamete from this individual that has the following genotype: alleles A and b, chromosome X?

Correct AnswerverifiedShow Answer

Calvin Bridges crossed white-eyed females to red-eyed males and found rare red-eyed males and white-eyed females in the progeny. Explain how he used the Drosophila sex determination system and nondisjunction to demonstrate that the gene for red/white eye color is on the X chromosome.

Correct AnswerAnswered by ExamLex AICalvin Bridges used the Drosophila sex d...View AnswerShow Answer

What is the sex chromosome constitution of a male duck-billed platypus?

Correct AnswerverifiedShow Answer

Correct AnswerAnswered by ExamLex AIAndrogen insensitivity syndrome (AIS) is...View AnswerShow Answer

An XXY chromosome constitution produces _____ development in humans and _____ development in fruit flies.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

In Drosophila, flies that are XXY but have a normal diploid set of autosomes have been found. Such XXY chromosome constitutions have also been found in humans. The sex of such individuals is expected to be:

Correct AnswerverifiedShow Answer

In which of the following individuals would you expect to find two Barr bodies in their somatic cells?

Correct AnswerverifiedShow Answer

Which of the following human genotypes is associated with Klinefelter syndrome?

Correct AnswerverifiedShow Answer

Normal males (XY) and Klinefelter males (XXY) both possess only one active X chromosome. Nonetheless, there are clearly phenotypic differences between the two. What is the MOST reasonable explanation as to why such differences exist?

Correct AnswerverifiedShow Answer

What is the expected outcome for a human embryo with the XXXY chromosome constitution?

Correct AnswerverifiedShow Answer

The Lyon hypothesis helps us to understand which phenomenon in mammals?

Correct AnswerverifiedShow Answer

A male has Klinefelter syndrome with the chromosome constitution of XXXY. How many Barr bodies should be found in the nuclei of cells of this individual?

Correct AnswerverifiedShow Answer

Correct AnswerAnswered by ExamLex AIRed-green color blindness is an X-linked...View AnswerShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
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Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
Answered by ExamLex AI
Calvin Bridges used the Drosophila sex d...
View Answer

Correct Answer
verified

Correct Answer
Answered by ExamLex AI
Androgen insensitivity syndrome (AIS) is...
View Answer

An XXY chromosome constitution produces _ development in humans and _ development in fruit flies.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
Answered by ExamLex AI
Red-green color blindness is an X-linked...
View Answer