Question 1

Regarding the human sex chromosomes, which statement is correct?

Accepted Answer

A)   The Y chromosome carries a greater number of genes for asexual traits than does the X chromosome.
B)   X and Y are different in size but carry nearly equal numbers of genes.
C)   The X chromosome carries more genes for asexual traits than does the Y.
D)   The X chromosome carries only gender-related genes.
E)   The X chromosome carries the genes for the development of male phenotype.

Question 2

What is the sequence of steps in preimplantation genetic diagnosis (PGD) ? 1. formation of 8-celled embryo
2)  induction of ovulation by hormones
3)  removal of 8-12 mature eggs
4)  fertilization by sperm in vitro
5)  screening of a cell from the embryo by DNA testing

Accepted Answer

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

Question 3

What is one difference between polyploidy and aneuploidy?

Accepted Answer

A)   Polyploidy is extra sets of chromosomes; aneuploidy does not increase by a full set.
B)   Humans can be viable as polyploids but not as aneuploids.
C)   Polyploidy is extra sex chromosomes; aneuploidy is extra autosomes.
D)   Polyploidy is one extra chromosome; aneuploidy is one missing chromosome.
E)   Polyploidy causes diseases and disorders in humans, aneuploidy does not.

Question 4

A nondisjunction event creates a human egg with one extra chromosome. If it is fertilized by a normal sperm, what is the total number of chromosomes in the zygote?

Accepted Answer

A)   47
B)   46
C)   45
D)   23
E)   22

Question 5

In a case of heterozygote advantage, it must be assumed that an allele has more than one effect on the phenotype of an organism.

Accepted Answer

A) True 
 B)False

Question 6

Why do X-linked conditions appear more frequently in males than in females?

Accepted Answer

A)   A male with a nonfunctioning allele on the X chromosome does not have another allele of that gene on the Y chromosome.
B)   Males have no X chromosomes.
C)   The Y chromosome carries many alleles that are recessive to alleles on the X.
D)   Males are more likely to inherit an extra chromosome than females.
E)   Females have no X chromosomes.

Question 7

It has been well documented that women above 40 have an increasing chance of giving birth to babies with Down syndrome. Why is this so?

Accepted Answer

A)   Egg development starts at the fetal stage of women.
B)   Eggs are in meiosis I at that time of fertilization.
C)   The egg doesn't complete division (meiosis II)  until fertilization.
D)   The cellular machinery is unable to separate the chromosomes and chromatids, resulting in gametes with abnormal chromosome numbers.
E)   All the above are true.

Question 8

A woman who is a carrier for the hemophilia gene has a child with a man who does not have hemophilia. Which prediction is correct?

Accepted Answer

A)   All of the sons and none of the daughters will have hemophilia.
B)   All of the daughters and none of the sons will have hemophilia.
C)   Half of the sons and half of the daughters will have hemophilia.
D)   Half of the sons and none of the daughters will have hemophilia.
E)   Half of the daughters and none of the sons will have hemophilia.

Question 9

What is preimplantation genetic diagnosis (PGD) ?

Accepted Answer

A)   allows screening of embryos in mother's uterus after 14 weeks of pregnancy
B)   allows screening of embryos before implantation in the uterus
C)   allows screening of embryos in mother's uterus after 7 weeks of pregnancy
D)   in vitro fertilization
E)   genetic screening of parents

Exam 12: Chromosomes and Inheritance

Why do X-linked conditions appear more frequently in males than in females?

Correct Answer
verified

It has been well documented that women above 40 have an increasing chance of giving birth to babies with Down syndrome. Why is this so?

Correct Answer
verified

Regarding the human sex chromosomes, which statement is correct?

Correct Answer
verified

A nondisjunction event creates a human egg with one extra chromosome. If it is fertilized by a normal sperm, what is the total number of chromosomes in the zygote?

Correct Answer
verified

In a case of heterozygote advantage, it must be assumed that an allele has more than one effect on the phenotype of an organism.

Correct Answer
verified

What is preimplantation genetic diagnosis (PGD) ?

Correct Answer
verified

A woman who is a carrier for the hemophilia gene has a child with a man who does not have hemophilia. Which prediction is correct?

Correct Answer
verified

What is the sequence of steps in preimplantation genetic diagnosis (PGD) ? 1. formation of 8-celled embryo 2) induction of ovulation by hormones 3) removal of 8-12 mature eggs 4) fertilization by sperm in vitro 5) screening of a cell from the embryo by DNA testing

Correct Answer
verified

What is one difference between polyploidy and aneuploidy?

Correct Answer
verified

Exam 12: Chromosomes and Inheritance

Why do X-linked conditions appear more frequently in males than in females?

Correct AnswerverifiedShow Answer

It has been well documented that women above 40 have an increasing chance of giving birth to babies with Down syndrome. Why is this so?

Correct AnswerverifiedShow Answer

Regarding the human sex chromosomes, which statement is correct?

Correct AnswerverifiedShow Answer

A nondisjunction event creates a human egg with one extra chromosome. If it is fertilized by a normal sperm, what is the total number of chromosomes in the zygote?

Correct AnswerverifiedShow Answer

In a case of heterozygote advantage, it must be assumed that an allele has more than one effect on the phenotype of an organism.

Correct AnswerverifiedShow Answer

What is preimplantation genetic diagnosis (PGD) ?

Correct AnswerverifiedShow Answer

A woman who is a carrier for the hemophilia gene has a child with a man who does not have hemophilia. Which prediction is correct?

Correct AnswerverifiedShow Answer

What is the sequence of steps in preimplantation genetic diagnosis (PGD) ? 1. formation of 8-celled embryo 2) induction of ovulation by hormones 3) removal of 8-12 mature eggs 4) fertilization by sperm in vitro 5) screening of a cell from the embryo by DNA testing

Correct AnswerverifiedShow Answer

What is one difference between polyploidy and aneuploidy?

Correct AnswerverifiedShow Answer

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