BIOL 4003 EXAM 1 QUESTIONS WITH
COMPLETE ANSWERS
Quiz 1: Let's suppose that true-breeding pea plants with purple flowers and yellow
seeds were crossed to true-breeding plants with white flowers and green seeds. The F1
plants had purple flowers that produced yellow seeds. The genes that affect these traits
independently assort. If the F1 plants were allowed to self-fertilize, the expected ratio of
the F2 generation would be:
3 purple flowers/yellow seeds : 1 white flowers/green seeds
9 purple flowers/yellow seeds: 3 white flowers/yellow seeds : 3 purple flowers/green
seeds : 1 white flowers/green seeds
9 white flowers/yellow seeds : 3 purple flowers/yellow seeds : 3 white flowers/green
seeds : 1 purple flowers/green seeds
1 white flowers/yellow seeds : 1 purple flowers/yellow seeds : 1 white flowers/green
seeds : 1 purple flowers/green seeds - ANSWER 9 purple flowers/yellow seeds: 3 white
flowers/yellow seeds : 3 purple flowers/green seeds : 1 white flowers/green seeds
Quiz 1: Which of the following statements is false?
An allele is a gene.
A true-breeding individual is homozygous.
A heterozygote has different alleles for a given gene.
,For most species, a chromosome carries a single gene. - ANSWER For most species, a
chromosome carries a single gene.
Quiz 1:
In humans, let's suppose an individual has a diploid set of autosomes and is XXY with
regard to their sex chromosomes. This person would be ____________ because
___________.
male, they have a Y chromosome.
female, they have two X
chromosomes.
female, the ratio of X
chromosomes to autosomes is 1.0
male, because they have a diploid set of autosomes - ANSWER male, they have a Y
chromosome.
Quiz 1: The pedigree below involves a genetic disease in humans. Affected individuals
are shown in black.
Autosomal dominant only
Autosomal recessive only
X-linked recessive only
, Autosomal dominant and autosomal recessive - ANSWER Autosomal dominant only
Quiz 1 If a rare dominant allele exerts its effect by antagonizing (inhibiting) the function
of the wild-type (normal) protein, this phenomenon is called
haploinsufficiency.
a gain-of-function mutation.
a dominant negative mutation.
overdominance. - ANSWER a dominant negative mutation.
Quiz 1: Flower color in the four o'clock plant exhibits incomplete dominance. A
red-flowered plant was crossed to white-flowered plant to obtain F1 plants. The F1
plants were then crossed to white-flowered plants to produce an F2 generation. The
expected ratio for the F2 plants would be:
1 red-flowered : 2 pink : 1 white-flowered
1 red-flowered : 1 white flowered
1 pink-flowered : 1 white flowered
All pink flowered - ANSWER 1 pink-flowered : 1 white flowered
Quiz 1 Hemophilia, type A, is an X-linked recessive trait. A mother without hemophilia
and a father with hemophilia have a son with hemophilia. They also have a daughter
named Amala. If we tested Amala's blood, the likelihood that she has hemophilia, type A
is
COMPLETE ANSWERS
Quiz 1: Let's suppose that true-breeding pea plants with purple flowers and yellow
seeds were crossed to true-breeding plants with white flowers and green seeds. The F1
plants had purple flowers that produced yellow seeds. The genes that affect these traits
independently assort. If the F1 plants were allowed to self-fertilize, the expected ratio of
the F2 generation would be:
3 purple flowers/yellow seeds : 1 white flowers/green seeds
9 purple flowers/yellow seeds: 3 white flowers/yellow seeds : 3 purple flowers/green
seeds : 1 white flowers/green seeds
9 white flowers/yellow seeds : 3 purple flowers/yellow seeds : 3 white flowers/green
seeds : 1 purple flowers/green seeds
1 white flowers/yellow seeds : 1 purple flowers/yellow seeds : 1 white flowers/green
seeds : 1 purple flowers/green seeds - ANSWER 9 purple flowers/yellow seeds: 3 white
flowers/yellow seeds : 3 purple flowers/green seeds : 1 white flowers/green seeds
Quiz 1: Which of the following statements is false?
An allele is a gene.
A true-breeding individual is homozygous.
A heterozygote has different alleles for a given gene.
,For most species, a chromosome carries a single gene. - ANSWER For most species, a
chromosome carries a single gene.
Quiz 1:
In humans, let's suppose an individual has a diploid set of autosomes and is XXY with
regard to their sex chromosomes. This person would be ____________ because
___________.
male, they have a Y chromosome.
female, they have two X
chromosomes.
female, the ratio of X
chromosomes to autosomes is 1.0
male, because they have a diploid set of autosomes - ANSWER male, they have a Y
chromosome.
Quiz 1: The pedigree below involves a genetic disease in humans. Affected individuals
are shown in black.
Autosomal dominant only
Autosomal recessive only
X-linked recessive only
, Autosomal dominant and autosomal recessive - ANSWER Autosomal dominant only
Quiz 1 If a rare dominant allele exerts its effect by antagonizing (inhibiting) the function
of the wild-type (normal) protein, this phenomenon is called
haploinsufficiency.
a gain-of-function mutation.
a dominant negative mutation.
overdominance. - ANSWER a dominant negative mutation.
Quiz 1: Flower color in the four o'clock plant exhibits incomplete dominance. A
red-flowered plant was crossed to white-flowered plant to obtain F1 plants. The F1
plants were then crossed to white-flowered plants to produce an F2 generation. The
expected ratio for the F2 plants would be:
1 red-flowered : 2 pink : 1 white-flowered
1 red-flowered : 1 white flowered
1 pink-flowered : 1 white flowered
All pink flowered - ANSWER 1 pink-flowered : 1 white flowered
Quiz 1 Hemophilia, type A, is an X-linked recessive trait. A mother without hemophilia
and a father with hemophilia have a son with hemophilia. They also have a daughter
named Amala. If we tested Amala's blood, the likelihood that she has hemophilia, type A
is
