Download 1 HONORS BIOLOGY HOMEWORK CHAPTER 11 MENDELIAN

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HONORS BIOLOGY
HOMEWORK CHAPTER 11
MENDELIAN GENETICS
1. A researcher performs a cross between a female pure, white,
albino rabbit and a coal-black lop-eared male. This
combination produced a random distribution of male/female
rabbits all having a gray coat.
The experimenters then crossed members of the F1 generation
and found the following distribution of coat color:
138 pure white rabbits
161 coal-black rabbits
312 gray coat rabbits
Indicate the genotype of the coat color of the
White albino rabbit
Coal-black rabbit
Gray coat rabbit
Explain the pattern of distribution seen as a result of the
above referenced crosses.
2. From the mating of two red-eyed, wild type fruit flies,
what would be the expected probability that
a. All of the first three offspring will be female?
b. All of the first three offspring will be male?
c. All of the siblings will be of the same sex?
d. Disregarding the birth order of the three siblings,
two will be female and one will be a male?
e. Disregarding the birth order, two will be male and one
female?
3. Two normal individuals with a family history of cystic
fibrosis plan to have children. The gene for cystic
fibrosis is a recessive autosomal allele. The father is
normal but his mother was diagnosed with the disease. The
mother is likewise normal but her father was affected with
the disease.
a. What are ALL of the possible outcomes from this union?
b. What is the probability if there are four children,
that all will be unaffected?
c. What is the probability if there are four children
that all four are affected?
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4. A plant, heterozygous for three independently assorting
genes, AaBbCc is self-fertilized. Among the offspring,
predict the frequency of
a. AABBCC individuals
b. aabbcc individuals
c. Individuals that are either AABBCC or aabbcc
d. AaBbCc individual
5. In pigeons, a dominant allele C carries a checkered pattern
in the feathers; its recessive allele c produces a plain
pattern. Feather coloration is controlled by an
independently assorting gene, the dominant allele B
produces red feathers and the recessive gene b produces
brown feathers. Birds from a true-breeding checkered, red
variety are crossed to birds from a true-breeding plain,
brown variety.
a. Predict the phenotype of the progeny
b. If these pigeons are “selfed”, what phenotypes will
appear in the F2 generation and in what proportion?
6. In cultivated flowers called “stocks”, pigment is
controlled by two independently assorting alleles. When the
dominant allele A is present at one locus, C_ at the other
locus leads to red pigmentation; cc leads to cream
pigmentation. The double recessive, aa, at the first locus
produces a white flower regardless of the alleles at the
second locus.
a. If a homozygous red stock is crossed with a white
variety, what phenotypic and genotypic ratios are
expected in the F1 and F2 generation?
b. If a cross between a red stock and a white stock
produces progeny of all three phenotypes, what are the
genotypes of the parents?
7. Niemann-Pick Disease, Gaucher’s Disease and Tay-Sachs
disease are all “lipid-storage diseases, more properly,
sphingolipidoses. Point out the similarities among these
conditions, both genotypically and phenotypically and
indicate what “non-Mendelian” condition they manifest.
If a normal mother has a defect for Gaucher’s disease
present on an X-chromosome, what will be the probability of
a son being affected if the father were also unaffected? If
the affected son were to have children with an unaffected
female, what would be the likelihood of his sons being
affected?
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8. Show the F1 genotype from the following parental cross and
then list the gametes that would result from a “self-cross”
of a male and female from that F1 result.
AABBCCDD X aabbccdd
9. Define the following terms (maximum two sentences):
a. Cosanguinous reproduction
b. Pleiotropy
c. Epistasis
d. Codominance
e. Incomplete dominance
f. Hemizygous
g. Reciprocal cross
h. Test cross
i. Polygenic traits
j. Multifactorial Traits
10.
A chromosomally normal woman and a chromosomally
normal man have a son whose sex-chromosome constitution is
XYY. In which parent, and in which meiotic division did the
nondisjunction take place?