Biol 4003 EXAM 1 questions well
answered passed
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 allowed to self-fertilize, the expected ratio of the F2
generation would be?
3 tall/purple flowers : 1 dwarf/white flowers
9 tall/purple flowers: 3 tall/white flowers : 3 dwarf/purple flowers : 1 dwarf /white flowers
9 tall/white flowers : 3 tall/purple flowers : 3 dwarf/white flowers : 1 dwarf/ purple flowers
1 tall/white flowers : 1 tall/purple flowers : 1 dwarf/white flowers : 1 dwarf/ purple flowers -
correct answer ✔✔ 9 tall/purple flowers: 3 tall/white flowers : 3 dwarf/purple flowers : 1
dwarf /white flowers
which is true
A homozygote has different alleles for a given gene.
An allele is a gene.
A true-breeding individual is heterozygous.
For most species, a chromosome carries a single gene. - correct answer ✔✔ an allele is a gene
,A fruit fly with a diploid set of autosomes has two X chromosomes and one Y chromosome. This
fly would be __________ because ____________.
male, it has a Y chromosome
male, the ratio of sex chromosomes to autosomes is 1.5
female, the ratio of X chromosomes to autosomes is 1.0
female, it has a diploid set of autosomes - correct answer ✔✔ female, the ratio of X
chromosomes to autosomes is 1.0
The pedigree below involves a genetic disease in humans. Affected individuals are shown in
black.
pic in canvas
Autosomal dominant only
Autosomal recessive only
X-linked recessive only
Autosomal dominant and autosomal recessive - correct answer ✔✔ autosomal dominant 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 - correct answer ✔✔ All of above
A trait exhibits incomplete dominance. If one of the two alleles is a loss-of-function allele, a
reasonable molecular explanation would be
The functional allele is up-regulated in the heterozygote.
The nonfunctional allele is up-regulated in the heterozygote
50% of the functional protein is not enough to give the same phenotype as 100%.
Both a and c are correct. - correct answer ✔✔ 50% of the functional protein is not enough to
give the same phenotype as 100%.
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
0%
25%
50%
100% - correct answer ✔✔ 50%
answered passed
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 allowed to self-fertilize, the expected ratio of the F2
generation would be?
3 tall/purple flowers : 1 dwarf/white flowers
9 tall/purple flowers: 3 tall/white flowers : 3 dwarf/purple flowers : 1 dwarf /white flowers
9 tall/white flowers : 3 tall/purple flowers : 3 dwarf/white flowers : 1 dwarf/ purple flowers
1 tall/white flowers : 1 tall/purple flowers : 1 dwarf/white flowers : 1 dwarf/ purple flowers -
correct answer ✔✔ 9 tall/purple flowers: 3 tall/white flowers : 3 dwarf/purple flowers : 1
dwarf /white flowers
which is true
A homozygote has different alleles for a given gene.
An allele is a gene.
A true-breeding individual is heterozygous.
For most species, a chromosome carries a single gene. - correct answer ✔✔ an allele is a gene
,A fruit fly with a diploid set of autosomes has two X chromosomes and one Y chromosome. This
fly would be __________ because ____________.
male, it has a Y chromosome
male, the ratio of sex chromosomes to autosomes is 1.5
female, the ratio of X chromosomes to autosomes is 1.0
female, it has a diploid set of autosomes - correct answer ✔✔ female, the ratio of X
chromosomes to autosomes is 1.0
The pedigree below involves a genetic disease in humans. Affected individuals are shown in
black.
pic in canvas
Autosomal dominant only
Autosomal recessive only
X-linked recessive only
Autosomal dominant and autosomal recessive - correct answer ✔✔ autosomal dominant 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 - correct answer ✔✔ All of above
A trait exhibits incomplete dominance. If one of the two alleles is a loss-of-function allele, a
reasonable molecular explanation would be
The functional allele is up-regulated in the heterozygote.
The nonfunctional allele is up-regulated in the heterozygote
50% of the functional protein is not enough to give the same phenotype as 100%.
Both a and c are correct. - correct answer ✔✔ 50% of the functional protein is not enough to
give the same phenotype as 100%.
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
0%
25%
50%
100% - correct answer ✔✔ 50%
