Question 1

If a genetic disorder is caused by a dominant allele, individuals with which of the following genotypes would be affected by the disorder?

Accepted Answer

A) AA and aa 
B) aa and Aa 
C) AA and Aa 
D) AA, Aa, and aa 
A) AA and aa 
B) aa and Aa 
C) AA and Aa 
D) AA, Aa, and aa C

Question 2

Sickle-cell disease is an inherited chronic blood disease caused by an autosomal recessive allele. Suppose a man who is homozygous recessive for the sickle-cell gene fathers a child by a woman who is a carrier for sickle-cell. What are the chances their children will exhibit the disease?

Accepted Answer

A) 0 percent 
B) 25 percent 
C) 50 percent 
D) 75 percent 
A) 0 percent 
B) 25 percent 
C) 50 percent 
D) 75 percent C

Question 3

Match each correct statement to the set of alleles listed below.
-male affected by recessive sex-linked disease

Accepted Answer

A) Bb 
B) XaY 
C) XAXa 
D) bb 
E) XAXA
F)BB
G)XAY 
A) Bb 
B) XaY 
C) XAXa 
D) bb 
E) XAXA
F)BB
G)XAY B

Question 4

Why are dominant genetic disorders more rare than recessive disorders?

Accepted Answer

Dominant genetic disorders tend to cause

Question 5

A karyotype shows a chromosomal abnormality that does not change the length of any of the chromosomes. Which abnormality is indicated?

Accepted Answer

A) inversion 
B) deletion 
C) translocation 
D) duplication 
A) inversion 
B) deletion 
C) translocation 
D) duplication

Question 6

If a father is affected by an X-linked condition and the mother is a carrier, what is the probability of their children being affected?

Accepted Answer

A) All sons will be affected. 
B) Half of the sons will be affected. 
C) All daughters will be affected. 
D) Half of the sons will be carriers. 
A) All sons will be affected. 
B) Half of the sons will be affected. 
C) All daughters will be affected. 
D) Half of the sons will be carriers.

Question 7

During cell division a piece of a chromosome breaks off and reattaches to the same chromosome, but the piece is now in reverse order. How would this abnormality affect the chromosome?

Accepted Answer

A) An extra copy of the chromosome will be made to ensure normal function. 
B) The inverted section will be deleted to prevent problems. 
C) The chromosome will take on a circular configuration. 
D) Genes in the section that was inverted could lose normal function. 
A) An extra copy of the chromosome will be made to ensure normal function. 
B) The inverted section will be deleted to prevent problems. 
C) The chromosome will take on a circular configuration. 
D) Genes in the section that was inverted could lose normal function.

Question 8

In the pedigree shown, the individual indicated represents a(n)

Accepted Answer

A) healthy male. 
B) healthy female. 
C) affected male. 
D) affected female. 
A) healthy male. 
B) healthy female. 
C) affected male. 
D) affected female.

Question 9

An individual who carries one copy of a recessive mutated allele and one normal copy is referred to as a genetic ________.

Accepted Answer

The answer of An individual who carries one copy of...

Question 10

On chromosomes within an individual, there are ________ alleles for a given gene found on ________ chromosomes.

Accepted Answer

A) two; homologous 
B) four; maternal 
C) four; paternal 
D) two; Y 
A) two; homologous 
B) four; maternal 
C) four; paternal 
D) two; Y

Question 11

Human males have one chromosome that females do not, known as the ________ chromosome.

Accepted Answer

The answer of Human males have one chromosome that females...

Question 12

Because an individual with an XX genotype is a female, is an individual with an XO (no second sex chromosome) a male?

Accepted Answer

A) No, because the X always overrides the Y and makes that embryo female. 
B) No, because the Y chromosome contains the gene that makes an embryo male. 
C) Yes, because if there is only one X, the embryo cannot become female. 
D) Yes, because all embryos start off as males. 
A) No, because the X always overrides the Y and makes that embryo female. 
B) No, because the Y chromosome contains the gene that makes an embryo male. 
C) Yes, because if there is only one X, the embryo cannot become female. 
D) Yes, because all embryos start off as males.

Question 13

If an individual has two alleles at a given locus that are different, the individual is said to be ________ for the gene.

Accepted Answer

The answer of If an individual has two alleles at...

Question 14

Which of the following statements would indicate a pedigree that shows the inheritance pattern of a recessive X-linked disease?

Accepted Answer

A) Most affected individuals are females. 
B) Most affected individuals are males. 
C) Males and females are affected equally. 
D) The disease is seen in every generation. 
A) Most affected individuals are females. 
B) Most affected individuals are males. 
C) Males and females are affected equally. 
D) The disease is seen in every generation.

Question 15

Explain how two brothers might have different X chromosomes, but they must share identical Y chromosomes.

Accepted Answer

Males inherit one of two X chr

Question 16

One chromosomal abnormality that is usually fatal is

Accepted Answer

A) a mutation in a gene. 
B) an exchange of material between homologous chromosomes. 
C) extra copies of sex chromosomes. 
D) the addition of an extra autosomal chromosome. 
A) a mutation in a gene. 
B) an exchange of material between homologous chromosomes. 
C) extra copies of sex chromosomes. 
D) the addition of an extra autosomal chromosome.

Question 17

Which of the following must be true for a woman who is heterozygous for a given gene?

Accepted Answer

A) She must be heterozygous for all genes. 
B) All of her eggs will contain both of the alleles for that gene. 
C) All of her eggs will contain one allele or the other, but not both alleles. 
D) She carries a rare mutation. 
A) She must be heterozygous for all genes. 
B) All of her eggs will contain both of the alleles for that gene. 
C) All of her eggs will contain one allele or the other, but not both alleles. 
D) She carries a rare mutation.

Question 18

Most inherited human disorders are the result of

Accepted Answer

A) recessive mutations of genes located on autosomes. 
B) dominant mutations of genes located on the X chromosome. 
C) recessive mutations of genes located on the Y chromosome. 
D) simultaneous mutations of the same gene on homologous chromosomes. 
A) recessive mutations of genes located on autosomes. 
B) dominant mutations of genes located on the X chromosome. 
C) recessive mutations of genes located on the Y chromosome. 
D) simultaneous mutations of the same gene on homologous chromosomes.

Question 19

A carrier is an individual with a ________ genotype who does not express the recessive trait but can pass it along to offspring.

Accepted Answer

A) homozygous 
B) heterozygous 
C) recessive 
D) dominant 
A) homozygous 
B) heterozygous 
C) recessive 
D) dominant

Question 20

Which of the following is true of the genetic cross shown in the figure?

Accepted Answer

A) All of their daughters will be carriers. 
B) Their sons have a 50 percent chance of being carriers. 
C) Their sons have a 50 percent chance of having the disorder. 
D) Their daughters have a 50 percent chance of having the disorder. 
A) All of their daughters will be carriers. 
B) Their sons have a 50 percent chance of being carriers. 
C) Their sons have a 50 percent chance of having the disorder. 
D) Their daughters have a 50 percent chance of having the disorder.

Exam 7: Chromosomes and Human Genetics

If a genetic disorder is caused by a dominant allele, individuals with which of the following genotypes would be affected by the disorder?

Sickle-cell disease is an inherited chronic blood disease caused by an autosomal recessive allele. Suppose a man who is homozygous recessive for the sickle-cell gene fathers a child by a woman who is a carrier for sickle-cell. What are the chances their children will exhibit the disease?

Match each correct statement to the set of alleles listed below. -male affected by recessive sex-linked disease

Why are dominant genetic disorders more rare than recessive disorders?

A karyotype shows a chromosomal abnormality that does not change the length of any of the chromosomes. Which abnormality is indicated?

If a father is affected by an X-linked condition and the mother is a carrier, what is the probability of their children being affected?

During cell division a piece of a chromosome breaks off and reattaches to the same chromosome, but the piece is now in reverse order. How would this abnormality affect the chromosome?

In the pedigree shown, the individual indicated represents a(n)

An individual who carries one copy of a recessive mutated allele and one normal copy is referred to as a genetic ________.

On chromosomes within an individual, there are ________ alleles for a given gene found on ________ chromosomes.

Human males have one chromosome that females do not, known as the ________ chromosome.

Because an individual with an XX genotype is a female, is an individual with an XO (no second sex chromosome) a male?

If an individual has two alleles at a given locus that are different, the individual is said to be ________ for the gene.

Which of the following statements would indicate a pedigree that shows the inheritance pattern of a recessive X-linked disease?

Explain how two brothers might have different X chromosomes, but they must share identical Y chromosomes.

One chromosomal abnormality that is usually fatal is

Which of the following must be true for a woman who is heterozygous for a given gene?

Most inherited human disorders are the result of

A carrier is an individual with a ________ genotype who does not express the recessive trait but can pass it along to offspring.

Which of the following is true of the genetic cross shown in the figure?

The Nature of Science

Chemistry of Life

Life Is Cellular

How Cells Work

Cell Division

Patterns of Inheritance

What Genes Are

How Genes Work

Evidence for Evolution

Mechanisms of Evolution

Adaptation and Species

The History of Life

Human Evolution

General Principles of Ecology

Growth of Populations

Communities of Organisms

Ecosystems

Homeostasis, Reproduction, and Development

Digestive, Muscular, and Skeletal Systems

Circulatory, Respiratory, Urinary, and Nervous Systems

Endocrine and Immune Systems

Plant Physiology

Applying the Science

Filters

On chromosomes within an individual, there are alleles for a given gene found on chromosomes.