Chapter 14 q&a
What do we mean when we use the terms monohybrid cross and dihybrid cross
A dihybrid cross involves organisms that are heterozygous for two characters and a monohybrid cross involves only one.
Why did the F₁ offspring of Mendel's classic pea cross always look like one of the two parental varieties?
One phenotype was completely dominant over another.
What was the most significant conclusion that Gregor Mendel drew from his experiments with pea plants?
Traits are inherited in discrete units, and are not the results of "blending."
How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEE?
8
Which of the following differentiates between independent assortment and segregation?
The law of independent assortment requires describing two or more genes relative to one another
A sexually reproducing animal has two unlinked genes, one for head shape (H) and one for tail length (T). Its genotype is HhTt. Which of the following genotypes is possible in a gamete from this organism?
HT
Mendel accounted for the observation that traits which had disappeared in the F₁ generation reappeared in the F₂ generation by proposing that
traits can be dominant or recessive, and the recessive traits were obscured by the dominant ones in the F₁.
Mendel was able to draw his ideas of segregation and independent assortment because of the influence of which of the following?
His reading of the scientific literature current in the field.
Mendel's observation of the segregation of alleles in gamete formation has its basis in which of the following phases of cell division?
anaphase I of meiosis
Mendel's second law of independent assortment has its basis in which of the following events of meiosis I?
alignment of tetrads at the equator
Which of the following describes the ability of a single gene to have multiple phenotypic effects?
pleiotropy
Which of the following is an example of polygenic inheritance?
skin pigmentation in humans
Which of the following provides an example of epistasis?
In rabbits and many other mammals, one genotype (cc) prevents any fur color from developing
The frequency of heterozygosity for the sickle-cell anemia allele is unusually high, presumably because this reduces the frequency of malaria. Such a relationship is related to which of the following
Darwin's explanation of natural selection
One of two major forms of a human condition called neurofibromatosis (NF 1) is inherited as a dominant gene, although it may range from mildly to very severely expressed. If a young child is the first in her family to be diagnosed, which of the following is the best explanation?
One of the parents has very mild expression of the gene.
A woman who has blood type A positive has a daughter who is type O
positive and a son who is type B negative. Rh positive is a trait that
shows simple dominance over Rh negative and is designated by the
alleles R and r, respectively. A third gene for the MN blood group has
codominant alleles M and N.
66) Which of the following is a possible partial genotype for
the son?
IBi
A woman who has blood type A positive has a daughter who is type O
positive and a son who is type B negative. Rh positive is a trait that
shows simple dominance over Rh negative and is designated by the
alleles R and r, respectively. A third gene for the MN blood group has
codominant alleles M and N.
67) Which of the following is a possible genotype for the mother?
IAi
A woman who has blood type A positive has a daughter who is type O
positive and a son who is type B negative. Rh positive is a trait that
shows simple dominance over Rh negative and is designated by the
alleles R and r, respectively. A third gene for the MN blood group has
codominant alleles M and N.
68) Which of the following is
B positive
A woman who has blood type A positive has a daughter who is type O
positive and a son who is type B negative. Rh positive is a trait that
shows simple dominance over Rh negative and is designated by the
alleles R and r, respectively. A third gene for the MN blood group has
codominant alleles M and N.
69) If both children are of blood type M, which of the following
is possible?
Each parent is either M or MN.