Question 1

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. 
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 2

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. 
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 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. 
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

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. 
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 5

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 
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

Question 6

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 
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 7

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

Question 8

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 9

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. 
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.

Exam 12: Chromosomes and Inheritance

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?

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

What is one difference between polyploidy and aneuploidy?

Regarding the human sex chromosomes, which statement is correct?

What is preimplantation genetic diagnosis (PGD)?

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

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?

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

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?

A Guide to the Natural World

Chemistry, Water and PH

Lifes Components: Biological Molecules

Lifes Home: The Cell

Lifes Border: The Plasma Membrane

An Introduction to Energy

Deriving Energy From Food

Photosynthesis

Genetics and Cell Division

Preparing for Sexual Reproduction: Meiosis

Mendel and His Discoveries

Dna Structure and Replication

Transcription Translation and Regulation

Biotechnology

Charles Darwin, Evolutionary Thought, and the Evidence for Evolution

Microevolution

Macroevolution

The History of Life on Earth

The Evolution of Human Beings

The Diversity of Life 1

The Diversity of Life 2

The Diversity of Life 3

An Introduction to Flowering Plants

Form and Function in Flowering Plants

The Integumentary Skeletal and Muscular Systems

The Nervous and Endocrine System

The Immune System

Blood and Breath

Digestion, Nutrition and Elimination

Animal Development

Human Reproduction

Populations in Ecology

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