PCB 3063 Exam 1 Questions and answers
Spring 2024 100% guaranteed pass
QUESTION 1
Beginning with a monohybrid cross of two true-breeding parents (AA X aa), what proportion of
the F2 generation will be homozygous recessive?
a. 1/8 b. 1/4 c. 1/3
d. 1/2
e. Cannot be determined from the information provided.
QUESTION 2
Which statement is false concerning the use of a testcross?
a. One parent contributes only recessive alleles.
b. It is useful in experiments to demonstrate independent assortment.
c. It is only useful for determining whether an allele is dominant or recessive.
d. The phenotype of the progeny from a testcross can determine whether a parent is heterozygous
for a recessive trait.
e. It can be used in experiments involving X-linked genes or genes on autosomal chromosomes.
QUESTION 3
One form of color blindness in humans results from an X-linked recessive gene. Which of the
statements below regarding the inheritance of the trait is false?
a. Heterozygous females transmit the allele causing color blindness to about half of their
daughters.
b. Males that inherit the recessive allele exhibit color blindness.
c. Heterozygous females have normal color vision. d. Color blindness can only occur in males.
PCB 3063 Exam 1
, e. Sons always inherit color blindness from their mother.
QUESTION 4
When a flower with yellow petals was crossed with another flower whose petals were red, all
the F1 heterozygotes displayed orange petals. The F2 phenotypic ratio of the offspring produced by the
self-fertilization of F1 individuals was: 1 yellow: 2 orange : 1 red. The alleles of this gene exhibit
a. Complete dominance
b. Codominance
c. Incomplete dominance
d. Epistatic interactions
e. More than one of the above
QUESTION 5
If the genotypes of two parents are AaBbCcDd and AaBbCcDd, what is the probability that a
daughter will be homozygous recessive for each of the four genes?
a. 1/16
b. 1/64
c. 1/256
d. 0
e. None of the above
QUESTION 6
Which of the following pairs are mismatched?
a. .
-chromosome in female cells of most species.
c.
d. nvolving an individual that is known to have recessive alleles for all of the
genes being tested.
e. None of the above are mismatched.
PCB 3063 Exam 1
Spring 2024 100% guaranteed pass
QUESTION 1
Beginning with a monohybrid cross of two true-breeding parents (AA X aa), what proportion of
the F2 generation will be homozygous recessive?
a. 1/8 b. 1/4 c. 1/3
d. 1/2
e. Cannot be determined from the information provided.
QUESTION 2
Which statement is false concerning the use of a testcross?
a. One parent contributes only recessive alleles.
b. It is useful in experiments to demonstrate independent assortment.
c. It is only useful for determining whether an allele is dominant or recessive.
d. The phenotype of the progeny from a testcross can determine whether a parent is heterozygous
for a recessive trait.
e. It can be used in experiments involving X-linked genes or genes on autosomal chromosomes.
QUESTION 3
One form of color blindness in humans results from an X-linked recessive gene. Which of the
statements below regarding the inheritance of the trait is false?
a. Heterozygous females transmit the allele causing color blindness to about half of their
daughters.
b. Males that inherit the recessive allele exhibit color blindness.
c. Heterozygous females have normal color vision. d. Color blindness can only occur in males.
PCB 3063 Exam 1
, e. Sons always inherit color blindness from their mother.
QUESTION 4
When a flower with yellow petals was crossed with another flower whose petals were red, all
the F1 heterozygotes displayed orange petals. The F2 phenotypic ratio of the offspring produced by the
self-fertilization of F1 individuals was: 1 yellow: 2 orange : 1 red. The alleles of this gene exhibit
a. Complete dominance
b. Codominance
c. Incomplete dominance
d. Epistatic interactions
e. More than one of the above
QUESTION 5
If the genotypes of two parents are AaBbCcDd and AaBbCcDd, what is the probability that a
daughter will be homozygous recessive for each of the four genes?
a. 1/16
b. 1/64
c. 1/256
d. 0
e. None of the above
QUESTION 6
Which of the following pairs are mismatched?
a. .
-chromosome in female cells of most species.
c.
d. nvolving an individual that is known to have recessive alleles for all of the
genes being tested.
e. None of the above are mismatched.
PCB 3063 Exam 1
