Biology Final: Chapter 15

Biology Final: Chapter 15

What name is given to the most common phenotype in a natural population?

wild type
mutant phenotype
locus
genotype
autosome

wild type
What can we observe in order to visualize Mendel’s Law of Segregation?

homologous chromosomes separating during meiosis II
the behavior of sex-linked genes
homologous chromosomes separating during meiosis I
sister chromatids separating during mitosis
the replication of DNA

homologous chromosomes separating during meiosis I
A white-eyed female Drosophila is crossed with a red-eyed male Drosophila. Which statement below correctly describes the results?

None of the females will have red eyes.
None of the females will have white eyes.
Fifty percent of the females will have red eyes.
Twenty-five percent of the females will have red eyes.
Twenty-five percent of the females will have white eyes.

None of the females will have white eyes.
Based on Bob and Eleanor’s family history, what inheritance pattern does the skin condition most likely follow?

autosomal dominant
X-linked recessive
autosomal recessive
Y-linked
X-linked dominant

X-linked dominant
A homozygous wild-type female fly is mated with a vermilion male fly.

Predict the eye colors of F1 and F2 generations. (Assume that the F1 flies are allowed to interbreed to produce the F2 generation.)

F1 females: all wild type
F1 males: all wild type
F2 females: all wild type
F2 males: 1/2 wild type, 1/2 vermilion
Red-green color blindness is due to an X-linked recessive allele in humans. A widow’s peak (a hairline that comes to a peak in the middle of the forehead) is due to an autosomal dominant allele.
Consider the following family history:
A man with a widow’s peak and normal color vision marries a color-blind woman with a straight hairline.
The man’s father had a straight hairline, as did both of the woman’s parents.
Use the family history to make predictions about the couple’s children.
If the couple has a child, what is the chance that it will be a son with a widow’s peak? 1/4

What is the chance that any son the couple has will be color blind with a straight hairline? 1/2

What is the chance that any daughter that the couple has will be color blind with a widow’s peak? 0

Suppose the couple had a daughter with normal color vision and a widow’s peak. What is the chance that she is heterozygous for both genes? 1

In humans, what determines the sex of offspring and why?

The female gamete determines sex because only the female gamete provides cytoplasm to the zygote.
The chromosome contribution from both parents determines sex because the offspring uses all the parents’ chromosomes.
The female gamete determines sex because only the female gametes can have one of two functional sex chromosomes.
The male determines sex because the sperm can fertilize either a female egg or a male egg.
The male gamete determines sex because each male gamete can contribute either an X or a Y chromosome.

The male gamete determines sex because each male gamete can contribute either an X or a Y chromosome.
In general, the frequency with which crossing over occurs between two linked genes depends on what?

the characters the genes code for
whether the genes are dominant or recessive
how far apart they are on the chromosome
whether the genes are on the X or some other chromosome
the phase of meiosis in which the crossing over occurs

how far apart they are on the chromosome
What is a nondisjunction?

An error in which a diploid cell or organism has an extra chromosome of one type, producing a chromosome number of 2n + 1
None of the above
An error in which a diploid cell or organism lacks a chromosome of one type, producing a chromosome number of 2n – 1
An error in cell division that causes homologous chromosomes or sister chromatids to move to the same side of the dividing cell

An error in cell division that causes homologous chromosomes or sister chromatids to move to the same side of the dividing cell
When can nondisjunction occur? Choose the best answer.

In meiosis, when homologous chromosomes fail to separate
In meiosis, when sister chromatids fail to separate
In mitosis, when sister chromatids fail to separate
All three answers are correct.

All three answers are correct.
Which syndrome is characterized by the XO chromosome abnormality?

Klinefelter syndrome
Trisomy X
Down syndrome
Turner syndrome

Turner syndrome
What kind of cell results when a diploid and a haploid gamete fuse during fertilization?

A monoploid cell
A monosomic cell
A triploid cell
A trisomic cell

A triploid cell
Of the following chromosomal abnormalities, which type is most likely to be viable in humans?

Monosomy
Triploidy
Trisomy
Haploidy

Trisomy
If a diploid cell undergoes meiosis and produces two gametes that are normal, and one with n − 1 chromosomes, and one with n + 1 chromosomes, what type of error occurred?

A nondisjunction error occurred in meiosis I, in which both members of all homologous pairs migrated to the same pole of the cell.

No error occurred; these are normal gametes.

A nondisjunction error occurred in meiosis II, in which both sister chromatids of a chromosome migrated to the same pole of the cell.

A nondisjunction error occurred in meiosis I, in which both members of a homologous pair migrated to the same pole of the cell.

A nondisjunction error occurred in meiosis II, in which both sister chromatids of a chromosome migrated to the same pole of the cell.
If a diploid cell undergoes meiosis and produces two gametes with n + 1 chromosomes and two gametes with n− 1 chromosomes, what type of error occurred?

A nondisjunction error occurred in meiosis I, in which both members of all homologous pairs migrated to the same pole of the cell.

A nondisjunction error occurred in meiosis I, in which both members of a homologous pair migrated to the same pole of the cell.

No error occurred; these are normal gametes.

A nondisjunction error occurred in meiosis II, in which both sister chromatids of a chromosome migrated to the same pole of the cell.

A nondisjunction error occurred in meiosis I, in which both members of a homologous pair migrated to the same pole of the cell.
Humans are diploid and have 46 chromosomes (or two sets). How many sets of chromosomes are found in each human gamete?

1
2
3
4
5

1
Humans are diploid and have 46 chromosomes. How many chromosomes are found in each human gamete?

12
23
36
45
92

23
_____ is the process by which haploid gametes form a diploid zygote.

Embryogenesis
Meiosis
Gastrulation
Fertilization
Mitosis

Fertilization
A particular diploid plant species has 48 chromosomes, or two sets. A mutation occurs and gametes with 48 chromosomes are produced. If self-fertilization occurs, the zygote will have _____ set(s) of chromosomes.

1
2
3
4
5

4
Which of these terms applies to an organism with extra sets of chromosomes?

monosomy
haploid
trisomy
polyploid
diploid

polyploid
Mutant tetraploid plants _____.

are usually sickly
are able to interbreed with their parents
have an odd number of chromosomes
are unable to interbreed with a diploid plant
unable to self-fertilize

are unable to interbreed with a diploid plant
Most polyploid plants arise as a result of _____.

self-fertilization
a mutation of gamete formation
meiosis
mitosis
hybridization

hybridization
Which of the following results in a situation in which the chromosome number is either 2n+1 or 2n-1 ?

polyploidy
gene linkage
inversion
aneuploidy
methylation

aneuploidy
What results if a fragment of a chromosome breaks off and then reattaches to the original chromosome at the same place but in the reverse direction?

a nondisjunction
polyploidy
a deletion
an inversion
a translocation

an inversion
What phenomenon occurs when a particular allele will either be expressed or silenced, depending on whether it is inherited from a male or a female?

aneuploidy
polyploidy
genomic imprinting
sex linkage
extranuclear inheritance

genomic imprinting
How are human mitochondria inherited?

as an X-linked trait
as linear DNA
without DNA
from the mother only
from the father only

from the mother only
Cystic fibrosis is an inherited disorder that affects which of the following?

lungs
heart
liver
All of the above.

All of the above.
How long can sperm be cryogenically stored and still be viable?

for more than 20 years
about 10 years
less than 2 years
only 6 months

for more than 20 years
Which federal agency ensures that sperm donors are tested for communicable diseases?

Food and Drug Administration
National Institutes of Health
Department of Health and Human Services
Centers for Disease Control

Food and Drug Administration
Which of the following is true?

Only women can be carriers for genetic disorders
Only men can be carriers for genetic disorders.
Neither women nor men can be carriers for genetic disorders.
Both women and men can be carriers for genetic disorders.

Both women and men can be carriers for genetic disorders.
Which of the following is a leading cause of sudden death among young athletes?

NF1
cystic fibrosis
Fragile X syndrome
HCM

HCM
Red-green color blindness is caused by a sex-linked recessive allele (color blindness is X-linked). A color-blind man marries a woman with normal vision whose father was color-blind.

What is the probability that they will have a color-blind daughter? Express your answer as a fraction using the slash symbol and no spaces (for example, 1/24).

1/4
What is the probability that their first son will be color-blind? Express your answer as a fraction using the slash symbol and no spaces (for example, 1/24).
1/2
Imagine a human disorder that is inherited as a dominant, X-linked trait. How would the frequency of this disorder vary between males and females?

Males would display this disorder with greater frequency than females.
Females would display this disorder with greater frequency than males.
Males and females would display this disorder with equal frequency

Females would display this disorder with greater frequency than males.