BIO 182 Exam 2 UPDATED ACTUAL
Exam Questions and CORRECT Answers
In a simple Mendelian monohybrid cross, true-breeding tall plants are crossed with short
plants, and the F1 plants, which are all tall, are allowed to self-pollinate. What fraction of the F2
generation are both tall and heterozygous?
a. 1⁄8
b. 1⁄4
c. 1⁄3
d. 2⁄3
e. 1⁄2 - CORRECT ANSWER - e. 1⁄2
The phenotype of an individual
a. depends at least in part on the genotype.
b. is either homozygous or heterozygous.
c. determines the genotype.
d. is the genetic constitution of the organism.
e. is either monohybrid or dihybrid. - CORRECT ANSWER - a. depends at least in part on
the genotype.
The ABO blood groups in humans are determined by a multiple-allele system in which IA and
IB are codominant and are both dominant to IO. A newborn infant is type A. The mother is type
O. Possible phenotypes of the father are
a. A, B, or AB.
b. A, B, or O.
c. O only.
d. A or AB.
e. A or O - CORRECT ANSWER - d. A or AB.
,Which statement about an individual that is homozygous for an allele is not true?
a. Each of its cells possesses two copies of that allele.
b. Each of its gametes contains one copy of that allele.
c. It is true-breeding with respect to that allele.
d. Its parents were necessarily homozygous for that allele.
e. It can pass that allele to its offspring. - CORRECT ANSWER - d. Its parents were
necessarily homozygous for that allele.
Which statement about a test cross is not true?
a. It tests whether an unknown individual is homozygous or heterozygous.
b. The test individual is crossed with a homozygous recessive individual.
c. If the test individual is heterozygous, the progeny will have a 1:1 ratio.
d. If the test individual is homozygous, the progeny will have a 3:1 ratio.
e. Test cross results are consistent with Mendel's model of inheritance for unlinked genes -
CORRECT ANSWER - d. If the test individual is homozygous, the progeny will have a
3:1 ratio
Linked genes
a. must be immediately adjacent to one another on a chromosome.
b. have alleles that assort independently of one another.
c. never show crossing over.
d. are on the same chromosome.
e. always have multiple alleles. - CORRECT ANSWER - d. are on the same chromosome.
In the F2 generation of a dihybrid cross
a. four phenotypes appear in the ratio 9:3:3:1 if the loci are linked.
b. four phenotypes appear in the ratio 9:3:3:1 if the loci are unlinked.
c. two phenotypes appear in the ratio 3:1 if the loci are unlinked.
d. three phenotypes appear in the ratio 1:2:1 if the loci are unlinked.
, e. two phenotypes appear in the ratio 1:1 whether or not the loci are linked. - CORRECT
ANSWER - b. four phenotypes appear in the ratio 9:3:3:1 if the loci are unlinked.
The genetic sex of a human is determined by
a. ploidy, with the male being haploid.
b. the Y chromosome.
c. X and Y chromosomes, the male being XX.
d. the number of X chromosomes, the male being XO.
e. Z and W chromosomes, the male being ZZ. - CORRECT ANSWER - b. the Y
chromosome.
In epistasis
a. nothing changes from generation to generation.
b. one gene alters the effect of another.
c. a portion of a chromosome is deleted.
d. a portion of a chromosome is inverted.
e. the behavior of two genes is entirely independent - CORRECT ANSWER - b. one gene
alters the effect of another.
In humans, spotted teeth are caused by a dominant sex-linked gene. A man with spotted teeth
whose father had normal teeth marries a woman with normal teeth. Therefore,
a. all of their daughters will have normal teeth.
b. all of their daughters will have spotted teeth.
c. all of their children will have spotted teeth.
d. half of their sons will have spotted teeth.
e. all of their sons will have spotted teeth. - CORRECT ANSWER - b. all of their
daughters will have spotted teeth.
Exam Questions and CORRECT Answers
In a simple Mendelian monohybrid cross, true-breeding tall plants are crossed with short
plants, and the F1 plants, which are all tall, are allowed to self-pollinate. What fraction of the F2
generation are both tall and heterozygous?
a. 1⁄8
b. 1⁄4
c. 1⁄3
d. 2⁄3
e. 1⁄2 - CORRECT ANSWER - e. 1⁄2
The phenotype of an individual
a. depends at least in part on the genotype.
b. is either homozygous or heterozygous.
c. determines the genotype.
d. is the genetic constitution of the organism.
e. is either monohybrid or dihybrid. - CORRECT ANSWER - a. depends at least in part on
the genotype.
The ABO blood groups in humans are determined by a multiple-allele system in which IA and
IB are codominant and are both dominant to IO. A newborn infant is type A. The mother is type
O. Possible phenotypes of the father are
a. A, B, or AB.
b. A, B, or O.
c. O only.
d. A or AB.
e. A or O - CORRECT ANSWER - d. A or AB.
,Which statement about an individual that is homozygous for an allele is not true?
a. Each of its cells possesses two copies of that allele.
b. Each of its gametes contains one copy of that allele.
c. It is true-breeding with respect to that allele.
d. Its parents were necessarily homozygous for that allele.
e. It can pass that allele to its offspring. - CORRECT ANSWER - d. Its parents were
necessarily homozygous for that allele.
Which statement about a test cross is not true?
a. It tests whether an unknown individual is homozygous or heterozygous.
b. The test individual is crossed with a homozygous recessive individual.
c. If the test individual is heterozygous, the progeny will have a 1:1 ratio.
d. If the test individual is homozygous, the progeny will have a 3:1 ratio.
e. Test cross results are consistent with Mendel's model of inheritance for unlinked genes -
CORRECT ANSWER - d. If the test individual is homozygous, the progeny will have a
3:1 ratio
Linked genes
a. must be immediately adjacent to one another on a chromosome.
b. have alleles that assort independently of one another.
c. never show crossing over.
d. are on the same chromosome.
e. always have multiple alleles. - CORRECT ANSWER - d. are on the same chromosome.
In the F2 generation of a dihybrid cross
a. four phenotypes appear in the ratio 9:3:3:1 if the loci are linked.
b. four phenotypes appear in the ratio 9:3:3:1 if the loci are unlinked.
c. two phenotypes appear in the ratio 3:1 if the loci are unlinked.
d. three phenotypes appear in the ratio 1:2:1 if the loci are unlinked.
, e. two phenotypes appear in the ratio 1:1 whether or not the loci are linked. - CORRECT
ANSWER - b. four phenotypes appear in the ratio 9:3:3:1 if the loci are unlinked.
The genetic sex of a human is determined by
a. ploidy, with the male being haploid.
b. the Y chromosome.
c. X and Y chromosomes, the male being XX.
d. the number of X chromosomes, the male being XO.
e. Z and W chromosomes, the male being ZZ. - CORRECT ANSWER - b. the Y
chromosome.
In epistasis
a. nothing changes from generation to generation.
b. one gene alters the effect of another.
c. a portion of a chromosome is deleted.
d. a portion of a chromosome is inverted.
e. the behavior of two genes is entirely independent - CORRECT ANSWER - b. one gene
alters the effect of another.
In humans, spotted teeth are caused by a dominant sex-linked gene. A man with spotted teeth
whose father had normal teeth marries a woman with normal teeth. Therefore,
a. all of their daughters will have normal teeth.
b. all of their daughters will have spotted teeth.
c. all of their children will have spotted teeth.
d. half of their sons will have spotted teeth.
e. all of their sons will have spotted teeth. - CORRECT ANSWER - b. all of their
daughters will have spotted teeth.
