Bio 133 / Bio133 Exam 2 (Latest 2026/
2027 Update) Questions & Answers |
Grade A | 100% Correct
Which of the following statements is NOT true of the sex chromosomes in humans?
The Y chromosome has fewer genes than the X chromosome.
Males produce two different kinds of gametes with respect to sex chromosomes.
Both the X and Y chromosome can undergo inactivation.
The presence of a functional Y chromosome causes an individual to develop into a male.
Both the X and Y chromosome can undergo inactivation.
A man without red-green colorblindness marries a woman who is a carrier for red-green
colorblindness. What is the probability that if they have a son, he will have red-green
colorblindness?
1/2
A man without red-green colorblindness marries a woman who is a carrier for red-green
colorblindness. If this same couple has a daughter, what is the probability that she will have
colorblindness?
0
,Bio 133 / Bio133 Exam 2 (Latest 2026/
2027 Update) Questions & Answers |
Grade A | 100% Correct
True or False: This pedigree represents possible X-linked dominant Inheritance (in this pedigree
- carriers are indicated with a dark circle).
Not possible - false
More males than females are affected by a disease with this inheritance pattern
X-Linked Recessive
If a female with red-green colorblindness has children with a man with normal vision - which of
the following statements is true?
All sons are expected to have red-green colorblindness.
Half of their sons are expected to have red-green colorblindness.
All of their daughters are expected to be carriers for red-green colorblindness.
Half of their daughters will have red-green colorblindness.
All of their daughters are expected to be carriers for red-green colorblindness.
,Bio 133 / Bio133 Exam 2 (Latest 2026/
2027 Update) Questions & Answers |
Grade A | 100% Correct
Occasionally mistakes can happen during meiosis and gametes can have more than one copy of a
chromosome. A person who ends up with the chromosomes XXY as a result of one of these
mistakes will usually be phenotypically
male due to the presence of a Y chromosome.
This is a picture of a male calico cat. Which of the following must be true of this cat? Select all
that apply.
He is XXY.
His cells will have a Barr body
He has a functional SRY gene.
He is heterozygous for the coat color allele.
He lacks the XIST gene.
Correct:
He is XXY.
His cells will have a Barr body
, Bio 133 / Bio133 Exam 2 (Latest 2026/
2027 Update) Questions & Answers |
Grade A | 100% Correct
He has a functional SRY gene.
He is heterozygous for the coat color allele.
Incorrect:
He lacks the XIST gene.
True or False. It is always the maternal X-chromosome that is inactivated during X-inactivation.
False - At a few thousand cell stage of the embryo the inactivation of one X chromosome occurs.
The X-chromosome is chosen at random, though once chosen it remains inactivated in all the
descendants of that cell.
You are working as a cytologist (scientists who study cells and cell abnormalities) and you are
given some cells from a male patient. You note that these cells all have a single Barr body. You
do further analysis and see that all cells also have a Y chromosome. Which of the following must
be true of this male patient?
The patient is XXY.
The patient is phenotypically female.
2027 Update) Questions & Answers |
Grade A | 100% Correct
Which of the following statements is NOT true of the sex chromosomes in humans?
The Y chromosome has fewer genes than the X chromosome.
Males produce two different kinds of gametes with respect to sex chromosomes.
Both the X and Y chromosome can undergo inactivation.
The presence of a functional Y chromosome causes an individual to develop into a male.
Both the X and Y chromosome can undergo inactivation.
A man without red-green colorblindness marries a woman who is a carrier for red-green
colorblindness. What is the probability that if they have a son, he will have red-green
colorblindness?
1/2
A man without red-green colorblindness marries a woman who is a carrier for red-green
colorblindness. If this same couple has a daughter, what is the probability that she will have
colorblindness?
0
,Bio 133 / Bio133 Exam 2 (Latest 2026/
2027 Update) Questions & Answers |
Grade A | 100% Correct
True or False: This pedigree represents possible X-linked dominant Inheritance (in this pedigree
- carriers are indicated with a dark circle).
Not possible - false
More males than females are affected by a disease with this inheritance pattern
X-Linked Recessive
If a female with red-green colorblindness has children with a man with normal vision - which of
the following statements is true?
All sons are expected to have red-green colorblindness.
Half of their sons are expected to have red-green colorblindness.
All of their daughters are expected to be carriers for red-green colorblindness.
Half of their daughters will have red-green colorblindness.
All of their daughters are expected to be carriers for red-green colorblindness.
,Bio 133 / Bio133 Exam 2 (Latest 2026/
2027 Update) Questions & Answers |
Grade A | 100% Correct
Occasionally mistakes can happen during meiosis and gametes can have more than one copy of a
chromosome. A person who ends up with the chromosomes XXY as a result of one of these
mistakes will usually be phenotypically
male due to the presence of a Y chromosome.
This is a picture of a male calico cat. Which of the following must be true of this cat? Select all
that apply.
He is XXY.
His cells will have a Barr body
He has a functional SRY gene.
He is heterozygous for the coat color allele.
He lacks the XIST gene.
Correct:
He is XXY.
His cells will have a Barr body
, Bio 133 / Bio133 Exam 2 (Latest 2026/
2027 Update) Questions & Answers |
Grade A | 100% Correct
He has a functional SRY gene.
He is heterozygous for the coat color allele.
Incorrect:
He lacks the XIST gene.
True or False. It is always the maternal X-chromosome that is inactivated during X-inactivation.
False - At a few thousand cell stage of the embryo the inactivation of one X chromosome occurs.
The X-chromosome is chosen at random, though once chosen it remains inactivated in all the
descendants of that cell.
You are working as a cytologist (scientists who study cells and cell abnormalities) and you are
given some cells from a male patient. You note that these cells all have a single Barr body. You
do further analysis and see that all cells also have a Y chromosome. Which of the following must
be true of this male patient?
The patient is XXY.
The patient is phenotypically female.
