ANSC 221 EXAM QUESTIONS AND
ANSWERS
What is the term used to describe that female mammals only produce gametes that
contain the X chromosome? - Answer-heterogametic
Adjustment of the number of active X chromosome alleles in females to equal that of
males is called? - Answer-segregation
Huntington disease is a rare dominant trait that causes neurodegeneration later in life. A
man in his thirties, who already has three children, discovers that his mother has
Huntington disease though his father is unaffected. What is the probability that the man
will develop Huntington disease? - Answer-1/2
. You set up a monohybrid cross between true breeding round winged and true breeding
oval winged insects. Your F1 offspring have round wings, and you collect the following
numbers of F2: Round wings: 302; Oval wings: 86. Which of the following statements is
NOT correct - Answer-The critical value for this chi square calculation is 7.815.
Independent assortment of chromosomes occurs during - Answer-meiosis
For the ABO blood system in humans, if an individual with the genotype IAIB is mated
with an individual that is IBIO, what fraction of offspring would have the phenotype A -
Answer-1/4
If a corn plant has the genotype AaBb, what is the probability of any given gamete from
the plant being ab? - Answer-¼
Double fertilization in plants is a process resulting in - Answer-two diploid embryos
formed that will give rise to two different seeds
If a pea plant has the genotype WwGg and the W and G loci are not linked, what is the
probability of producing a gamete that is wG - Answer-1/4
If two WwGg individuals are mated, what is the probability of producing WwGG offspring
- Answer-1/8
, Yellow mice are intermated. The offspring are 15 gray and 31 yellow mice. The most
likely explanation for this ratio is: - Answer-incomplete dominance
Huntington disease is a rare dominant trait that causes neurodegeneration later in life. A
man in his thirties, who already has three children, discovers that his mother has
Huntington disease though his father is unaffected. What is the probability that the man
will develop Huntington disease - Answer-1/2
You capture several interesting insects from a population in your yard. By inbreeding,
you develop true breeding strains that differ only in the shape of their wings - one strain
has round wings while the other strain has oval wings. How might you demonstrate that
Mendel's principles apply to your insects - Answer-Set up a monohybrid cross and
determine if your F2 results are predicted by a 3:1 ratio based on the law of
segregation.
I know that black coat color in mice is dominant to albino. Black mice get a higher price
at the pet store so I am disappointed when I cross a black mouse with an albino mouse
and get 6 albino and 2 black mice in the litter. I expected all black. What mistake did I
make - Answer-I assumed that my black mouse was true-breeding.
If two chromosomes are homologous, they - Answer-a. look similar under a microscope.
b. have very similar DNA sequences.
c. carry the same types of genes.
d. may carry different versions of the same gene.
E. are all of the above
Which of the following is an event of prophase of mitosis - Answer-The nuclear
envelope begins to break down.
A student is looking at cells under the microscope. The cells are from an organism that
has a diploid number of 14. In one particular case, the cell has seven pairs of
homologous replicated chromosomes aligned at the metaphase plate of the cell. Which
of the following statements accurately describes this particular cell? - Answer-The cell is
in metaphase of meiosis II
Which of the following statements accurately describes a difference between mitosis
and meiosis? - Answer-a. Mitosis may produce diploid cell, whereas meiosis produces
haploid cells.
b. Homologous chromosomes synapse during meiosis, but do not synapse during
mitosis.
c. Crossing over commonly occurs during meiosis, but it does not commonly occur
during mitosis.
D. All of the above are correct.
During crossing over in meiosis I, - Answer-homologous chromosomes exchange
genetic material.
ANSWERS
What is the term used to describe that female mammals only produce gametes that
contain the X chromosome? - Answer-heterogametic
Adjustment of the number of active X chromosome alleles in females to equal that of
males is called? - Answer-segregation
Huntington disease is a rare dominant trait that causes neurodegeneration later in life. A
man in his thirties, who already has three children, discovers that his mother has
Huntington disease though his father is unaffected. What is the probability that the man
will develop Huntington disease? - Answer-1/2
. You set up a monohybrid cross between true breeding round winged and true breeding
oval winged insects. Your F1 offspring have round wings, and you collect the following
numbers of F2: Round wings: 302; Oval wings: 86. Which of the following statements is
NOT correct - Answer-The critical value for this chi square calculation is 7.815.
Independent assortment of chromosomes occurs during - Answer-meiosis
For the ABO blood system in humans, if an individual with the genotype IAIB is mated
with an individual that is IBIO, what fraction of offspring would have the phenotype A -
Answer-1/4
If a corn plant has the genotype AaBb, what is the probability of any given gamete from
the plant being ab? - Answer-¼
Double fertilization in plants is a process resulting in - Answer-two diploid embryos
formed that will give rise to two different seeds
If a pea plant has the genotype WwGg and the W and G loci are not linked, what is the
probability of producing a gamete that is wG - Answer-1/4
If two WwGg individuals are mated, what is the probability of producing WwGG offspring
- Answer-1/8
, Yellow mice are intermated. The offspring are 15 gray and 31 yellow mice. The most
likely explanation for this ratio is: - Answer-incomplete dominance
Huntington disease is a rare dominant trait that causes neurodegeneration later in life. A
man in his thirties, who already has three children, discovers that his mother has
Huntington disease though his father is unaffected. What is the probability that the man
will develop Huntington disease - Answer-1/2
You capture several interesting insects from a population in your yard. By inbreeding,
you develop true breeding strains that differ only in the shape of their wings - one strain
has round wings while the other strain has oval wings. How might you demonstrate that
Mendel's principles apply to your insects - Answer-Set up a monohybrid cross and
determine if your F2 results are predicted by a 3:1 ratio based on the law of
segregation.
I know that black coat color in mice is dominant to albino. Black mice get a higher price
at the pet store so I am disappointed when I cross a black mouse with an albino mouse
and get 6 albino and 2 black mice in the litter. I expected all black. What mistake did I
make - Answer-I assumed that my black mouse was true-breeding.
If two chromosomes are homologous, they - Answer-a. look similar under a microscope.
b. have very similar DNA sequences.
c. carry the same types of genes.
d. may carry different versions of the same gene.
E. are all of the above
Which of the following is an event of prophase of mitosis - Answer-The nuclear
envelope begins to break down.
A student is looking at cells under the microscope. The cells are from an organism that
has a diploid number of 14. In one particular case, the cell has seven pairs of
homologous replicated chromosomes aligned at the metaphase plate of the cell. Which
of the following statements accurately describes this particular cell? - Answer-The cell is
in metaphase of meiosis II
Which of the following statements accurately describes a difference between mitosis
and meiosis? - Answer-a. Mitosis may produce diploid cell, whereas meiosis produces
haploid cells.
b. Homologous chromosomes synapse during meiosis, but do not synapse during
mitosis.
c. Crossing over commonly occurs during meiosis, but it does not commonly occur
during mitosis.
D. All of the above are correct.
During crossing over in meiosis I, - Answer-homologous chromosomes exchange
genetic material.
