GENETICS EXAM 2 AND ITS
CORRECT REVIEWED SOLUTIONS
albinism, lack of pigmentation in humans, results from
an autosomal recessive gene (a). two parents with
normal pigmentation have an albino child. what is the
probability that their next three children will be an
albino?
1/64
- Aa x Aa will results in 1/4 possibility of albinism. for the
probability of three children to have it you multiply 1/4 to
itself three times.
the genotypes of husband and wife are I^A and I^B.
among the blood types of their children, how many
different genotypes and phenotypes are possible?
4 genotypes, 3 phenotypes
incompletely penetrant genes are ones that
are expressed in some individuals but not others
tightly curled or wooly hair is caused by a dominant
gene in humans. if a heterozygous curly-haired person
marries a person with straight hair, what percentage
of their offspring would be expected to have straight
hair?
50% straight
with which of the following would hemizygosity most
likely be associated?
x-linked inheritance
what happens during early metaphase of mitosis?
, chromosomes align at metaphase plate
hemophilia is determined by a gene on the X
chromosome in humans. assume that a
phenotypically normal woman whose father had
hemophilia is married to a normal man. what is the
probability that their first daughter will have
hemophilia? what is the probability that their son will
have hemophilia?
0%, 50%
Assume that a cross is made between AaBb and aabb
plants and that all the offspring are either AaBb or
aabb. These results are consistent with the following
circumstance:
complete linkage (genes on the same chromosome but no
cross over between them)
for chi square analysis, the closer the observed
values are to the expected values
the smaller the chi square value is
which of the following is a reason why the daughter
cells that result from the process of meiosis are not
genetically identical to the parent cell at the beginning
of the process?
All of these
- crossing over
- each homologous chromosome in a pair is inherited from
a different parent
- each homologue randomly asserts into a daughter cell
altered forms of the wild type allele are also
commonly known as
mutants
CORRECT REVIEWED SOLUTIONS
albinism, lack of pigmentation in humans, results from
an autosomal recessive gene (a). two parents with
normal pigmentation have an albino child. what is the
probability that their next three children will be an
albino?
1/64
- Aa x Aa will results in 1/4 possibility of albinism. for the
probability of three children to have it you multiply 1/4 to
itself three times.
the genotypes of husband and wife are I^A and I^B.
among the blood types of their children, how many
different genotypes and phenotypes are possible?
4 genotypes, 3 phenotypes
incompletely penetrant genes are ones that
are expressed in some individuals but not others
tightly curled or wooly hair is caused by a dominant
gene in humans. if a heterozygous curly-haired person
marries a person with straight hair, what percentage
of their offspring would be expected to have straight
hair?
50% straight
with which of the following would hemizygosity most
likely be associated?
x-linked inheritance
what happens during early metaphase of mitosis?
, chromosomes align at metaphase plate
hemophilia is determined by a gene on the X
chromosome in humans. assume that a
phenotypically normal woman whose father had
hemophilia is married to a normal man. what is the
probability that their first daughter will have
hemophilia? what is the probability that their son will
have hemophilia?
0%, 50%
Assume that a cross is made between AaBb and aabb
plants and that all the offspring are either AaBb or
aabb. These results are consistent with the following
circumstance:
complete linkage (genes on the same chromosome but no
cross over between them)
for chi square analysis, the closer the observed
values are to the expected values
the smaller the chi square value is
which of the following is a reason why the daughter
cells that result from the process of meiosis are not
genetically identical to the parent cell at the beginning
of the process?
All of these
- crossing over
- each homologous chromosome in a pair is inherited from
a different parent
- each homologue randomly asserts into a daughter cell
altered forms of the wild type allele are also
commonly known as
mutants
