Biology 111- Chapter 15 Test Bank
Latest Verified Review 2024 Practice Questions and
Answers for Exam Preparation, 100% Correct
When Thomas Hunt Morgan crossed his red-eyed F1 generation flies to each other, the
F2 generation included both red- and white-eyed flies. Remarkably, all the white-eyed
flies were male. What was the explanation for this result?
✔The gene involved is on the X chromosome.
Which of the following is the meaning of the chromosome theory of inheritance as
expressed in the early twentieth century?
✔Mendelian genes are at specific loci on the chromosome and, in turn, segregate during
meiosis.
Males are more often affected by sex-linked traits than females because _____
. ✔males are hemizygous for the X chromosome
SRY is best described as _____.
✔a gene region present on the Y chromosome that triggers male development
In cats, black fur color is caused by an X-linked allele; the other allele at this locus causes
orange color. The heterozygote is tortoiseshell. What kinds of offspring would you expect
from the cross of a black female and an orange male?
✔tortoiseshell females; black males
Red-green color blindness is a sex-linked recessive trait in humans. Two people with
normal color vision have a color-blind son. What are the genotypes of the parents?
✔XNXn and XNY
, Biology 111- Chapter 15 Test Bank
Latest Verified Review 2024 Practice Questions and
Answers for Exam Preparation, 100% Correct
Cinnabar eyes is a sex-linked, recessive characteristic in fruit flies. If a female having
cinnabar eyes is crossed with a wild-type male, what percentage of the F1 males will
have cinnabar eyes?
✔100%
Normally, only female cats have the tortoiseshell phenotype because _____.
✔a male inherits only one allele of the X-linked gene controlling hair color
In birds, sex is determined by a ZW chromosome scheme. Males are ZZ and females are
ZW. A recessive lethal allele that causes death of the embryo is sometimes present on the
Z chromosome in pigeons. What would be the sex ratio in the offspring of a cross
between a male that is heterozygous for the lethal allele and a normal female?
✔2:1 male to female
Sex determination in mammals is due to the SRY gene. Which of the following could
allow a person with an XX karyotype to develop a male phenotype?
✔translocation of SRY to a X chromosome
In humans, clear gender differentiation occurs, not at fertilization, but after the second
month of gestation. What is the first event of this differentiation?
✔activation of SRY in male embryos and masculinization of the gonads
Latest Verified Review 2024 Practice Questions and
Answers for Exam Preparation, 100% Correct
When Thomas Hunt Morgan crossed his red-eyed F1 generation flies to each other, the
F2 generation included both red- and white-eyed flies. Remarkably, all the white-eyed
flies were male. What was the explanation for this result?
✔The gene involved is on the X chromosome.
Which of the following is the meaning of the chromosome theory of inheritance as
expressed in the early twentieth century?
✔Mendelian genes are at specific loci on the chromosome and, in turn, segregate during
meiosis.
Males are more often affected by sex-linked traits than females because _____
. ✔males are hemizygous for the X chromosome
SRY is best described as _____.
✔a gene region present on the Y chromosome that triggers male development
In cats, black fur color is caused by an X-linked allele; the other allele at this locus causes
orange color. The heterozygote is tortoiseshell. What kinds of offspring would you expect
from the cross of a black female and an orange male?
✔tortoiseshell females; black males
Red-green color blindness is a sex-linked recessive trait in humans. Two people with
normal color vision have a color-blind son. What are the genotypes of the parents?
✔XNXn and XNY
, Biology 111- Chapter 15 Test Bank
Latest Verified Review 2024 Practice Questions and
Answers for Exam Preparation, 100% Correct
Cinnabar eyes is a sex-linked, recessive characteristic in fruit flies. If a female having
cinnabar eyes is crossed with a wild-type male, what percentage of the F1 males will
have cinnabar eyes?
✔100%
Normally, only female cats have the tortoiseshell phenotype because _____.
✔a male inherits only one allele of the X-linked gene controlling hair color
In birds, sex is determined by a ZW chromosome scheme. Males are ZZ and females are
ZW. A recessive lethal allele that causes death of the embryo is sometimes present on the
Z chromosome in pigeons. What would be the sex ratio in the offspring of a cross
between a male that is heterozygous for the lethal allele and a normal female?
✔2:1 male to female
Sex determination in mammals is due to the SRY gene. Which of the following could
allow a person with an XX karyotype to develop a male phenotype?
✔translocation of SRY to a X chromosome
In humans, clear gender differentiation occurs, not at fertilization, but after the second
month of gestation. What is the first event of this differentiation?
✔activation of SRY in male embryos and masculinization of the gonads
