PCB 3063 FINAL EXAM QUESTIONS & ANSWERS
Which of the following events of meiosis creates genetic variation among the gametes?
A. Crossing over
B. Independent assortment of maternal and paternal chromosomes
C. Separation of homologues so each gamete only gets one copy of each chromosome
D. A and B
E. All of the above - Answers :E. All of the above
Tall (T) is a dominant trait in corn plants over dwarf (t). A tall plant is test-crossed, and
half of the offspring produced are tall and half are dwarf. What are the genotypes of the
individuals that were crossed if the mating followed exactly what was predicted?
A. TT x tt
B. Tt x tt
C. Tt x Tt
D. TT x Tt - Answers :B. Tt x tt
For the recessive X-linked eye color gene in fruit flies, Morgan crossed a homozygous
red eyed female with a white eyed male. Which result made Morgan think that the locus
affecting eye color was on the X chromosome?
A. All F1 male and female flies had red eyes.
B. All F1 male and female flies had white eyes.
C. In the F2, all females had red eyes, and half of the males had red eyes and the other
half had white eyes.
D. In the F2, half of males and females had red eyes and the other half had white eyes.
- Answers :C. In the F2, all females had red eyes, and half of the males had red eyes
and the other half had white eyes.
A child who is blood type A has a mother who is blood type B. In a paternity suit, a man
is accused of being the father. He has blood type AB. Is he the father?
A. Yes for sure
B. No for sure
C. He can not be excluded at this point.
D. There is a 50% chance he is the father. - Answers :C. He can not be excluded at this
, point.
If the mom is IBi, he could be the father.
What characteristic would you NOT expect to see in a pedigree of an X-linked recessive
trait?
A. The trait is more commonly seen in males.
B. The trait can skip a generation.
C. The trait is commonly passed from fathers to sons.
D. Whenever a daughter receives the trait, the father is affected.
E. An affected son's mother either has the trait or is heterozygous (carrier). - Answers
:C. The trait is commonly passed from fathers to sons.
Which of the following is NOT an assumption of the Hardy-Weinberg law?
A. Large populations
B. No natural selection
C. Non-random mating
D. No gene flow
E. No mutations - Answers :C. Non-random mating
Consider the following three-point cross:
ABCxabc
abcabc
Which of the following is NOT a possible progeny genotype? (Consider both
recombinant and non-recombinant progeny.)
A. A B C
abc
Which of the following events of meiosis creates genetic variation among the gametes?
A. Crossing over
B. Independent assortment of maternal and paternal chromosomes
C. Separation of homologues so each gamete only gets one copy of each chromosome
D. A and B
E. All of the above - Answers :E. All of the above
Tall (T) is a dominant trait in corn plants over dwarf (t). A tall plant is test-crossed, and
half of the offspring produced are tall and half are dwarf. What are the genotypes of the
individuals that were crossed if the mating followed exactly what was predicted?
A. TT x tt
B. Tt x tt
C. Tt x Tt
D. TT x Tt - Answers :B. Tt x tt
For the recessive X-linked eye color gene in fruit flies, Morgan crossed a homozygous
red eyed female with a white eyed male. Which result made Morgan think that the locus
affecting eye color was on the X chromosome?
A. All F1 male and female flies had red eyes.
B. All F1 male and female flies had white eyes.
C. In the F2, all females had red eyes, and half of the males had red eyes and the other
half had white eyes.
D. In the F2, half of males and females had red eyes and the other half had white eyes.
- Answers :C. In the F2, all females had red eyes, and half of the males had red eyes
and the other half had white eyes.
A child who is blood type A has a mother who is blood type B. In a paternity suit, a man
is accused of being the father. He has blood type AB. Is he the father?
A. Yes for sure
B. No for sure
C. He can not be excluded at this point.
D. There is a 50% chance he is the father. - Answers :C. He can not be excluded at this
, point.
If the mom is IBi, he could be the father.
What characteristic would you NOT expect to see in a pedigree of an X-linked recessive
trait?
A. The trait is more commonly seen in males.
B. The trait can skip a generation.
C. The trait is commonly passed from fathers to sons.
D. Whenever a daughter receives the trait, the father is affected.
E. An affected son's mother either has the trait or is heterozygous (carrier). - Answers
:C. The trait is commonly passed from fathers to sons.
Which of the following is NOT an assumption of the Hardy-Weinberg law?
A. Large populations
B. No natural selection
C. Non-random mating
D. No gene flow
E. No mutations - Answers :C. Non-random mating
Consider the following three-point cross:
ABCxabc
abcabc
Which of the following is NOT a possible progeny genotype? (Consider both
recombinant and non-recombinant progeny.)
A. A B C
abc
