BIOL 4003 quizzes with complete
solutions
True-breeding tall plants with purple flowers are crossed to true-breeding dwarf plants with
white flowers. The F1 plants were tall with purple flowers. The genes that affect these traits
independently assort. If the F1 plants were crossed to dwarf plants with white flowers, the
expected ratio of the F2 generation would be - ANS ✔✔9 tall/purple flowers:
3 tall/white flowers :
3 dwarf/purple flowers :
1 dwarf /white flowers
Which of the following statements is false?
A homozygote has different alleles for a given gene.
A chromosome carries many genes.
An allele is a gene
A true-breeding individual is homozygous - ANS ✔✔A homozygote has different alleles for a
given gene.
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 ___________. - ANS
✔✔male, they have a Y chromosome
The pedigree below involves a genetic disease in humans. Affectedindividuals are shown in
black.
, Which of the following patterns is/are consistent with this pedigree? - ANS ✔✔Autosomal
recessive only
Which of the following is a molecular explanation for dominance exerted by rare dominant
alleles?
Haploinsufficiency
Gain of function mutation
Dominant negative mutation
All of the above - ANS ✔✔All of the above
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 -
ANS ✔✔1 pink-flowered : 1 white flowered
According to the chromosome theory of inheritance, Mendel's law of segregation can be
explained by the - ANS ✔✔separation of homologs during anaphase of meiosis I.
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 - ANS ✔✔50%
In certain breeds of cattle, having scurs is a sex-influenced trait. Having scurs is dominant in
males and not having scurs is dominant in females. If a bull (male) without scurs is crossed to a
cow (female) with scurs, what are the possible phenotypes of the offspring? - ANS ✔✔males
with scurs and females without scurs
solutions
True-breeding tall plants with purple flowers are crossed to true-breeding dwarf plants with
white flowers. The F1 plants were tall with purple flowers. The genes that affect these traits
independently assort. If the F1 plants were crossed to dwarf plants with white flowers, the
expected ratio of the F2 generation would be - ANS ✔✔9 tall/purple flowers:
3 tall/white flowers :
3 dwarf/purple flowers :
1 dwarf /white flowers
Which of the following statements is false?
A homozygote has different alleles for a given gene.
A chromosome carries many genes.
An allele is a gene
A true-breeding individual is homozygous - ANS ✔✔A homozygote has different alleles for a
given gene.
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 ___________. - ANS
✔✔male, they have a Y chromosome
The pedigree below involves a genetic disease in humans. Affectedindividuals are shown in
black.
, Which of the following patterns is/are consistent with this pedigree? - ANS ✔✔Autosomal
recessive only
Which of the following is a molecular explanation for dominance exerted by rare dominant
alleles?
Haploinsufficiency
Gain of function mutation
Dominant negative mutation
All of the above - ANS ✔✔All of the above
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 -
ANS ✔✔1 pink-flowered : 1 white flowered
According to the chromosome theory of inheritance, Mendel's law of segregation can be
explained by the - ANS ✔✔separation of homologs during anaphase of meiosis I.
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 - ANS ✔✔50%
In certain breeds of cattle, having scurs is a sex-influenced trait. Having scurs is dominant in
males and not having scurs is dominant in females. If a bull (male) without scurs is crossed to a
cow (female) with scurs, what are the possible phenotypes of the offspring? - ANS ✔✔males
with scurs and females without scurs
