Download Biology Ch 8 Review Answers - the Bee

R. H. Beeman
Chapter 8 Mendel’s Genetics) Review
Biology I
Text pages 184, 185
page 1 of 4
1. The scientist whose studies formed the basis of modern genetics is
a. T. A. Knight.
b. Gregor Mendel.
c. Louis Pasteur.
d. Robert Hooke
2. Which of the following is not a good reason why Pisum sativum makes an
excellent subject for genetic study?
a. Many varieties exist.
b. They require cross-pollination.
c. They grow quickly.
d. They demonstrate complete dominance.
3. If smooth peas are dominant over wrinkled peas, the allele for smooth peas
should be represented as
a. W
b. S
c. w
d. s
4. The law of segregation states that pairs of alleles
a. Separate when gametes form.
b. Separate independently of one another during gamete formation.
c. Are always the same.
d. Are always different.
5. The trait shown is
a. Sex-linked and dominant.
b. Autosomal and dominant.
c. Sex-linked and recessive.
d. Autosomal and recessive.
6. D, dimples, is the dominant allele to the recessive allele, d, no dimples. The
probability of parents with Dd and dd genotypes having a child with no dimples
(dd) is
a. 1/8
b. ¼
c. ½
d. 1
R. H. Beeman
Chapter 8 Mendel’s Genetics) Review
Biology I
Text pages 184, 185
page 2 of 4
7. The unknown genotype of an individual with a dominant phenotype can be
determined using
a. A ratio.
b. A dihybrid cross.
c. probability.
d. A test cross.
8. Explain how working genes have been inserted into defective cells during gene
therapy.
9. Relate the events of meiosis to the law of segregation. (hint: see chapter 7,
section 1.)
10. State the genotypic and phenotypic ratios that would result from a cross between
two YyRR pea plants.
12. Evaluating Results Mendel based his conclusion about inheritance patterns on
experiments involving large numbers of plants. Why do you think the use of
large numbers of individuals is advantageous when studying patterns of
inheritance?
13. Justifying Conclusions A 20 year-old man who has cystic fibrosis has a sister
who is planning to have a child. The man encourages his sister to see a genetic
counselor. What do you think the man’s reasons are for giving such advice?
1. What are the offspring of true-breeding parents called?
a. F1 generation.
b. F2 generation.
c. Dominant offspring.
d. Recessive offspring.
2. A man and a woman who do not have hemophilia visit a genetic counselor.
What tool might the counselor use to determine the risk of the couple having a
child with hemophilia?
f. blood test.
g. DNA fingerprint.
h. Karyotype.
i. Pedigree.
R. H. Beeman
Chapter 8 Mendel’s Genetics) Review
Biology I
Text pages 184, 185
page 3 of 4
3. What characteristic is described in the statement: The dog’s coat is brown?
a. Dominance
b. Genotype
c. Pedigree
d. Phenotype
4. Albinism is rare among wild animals, but common among some domesticated
species. What factor might account for this difference?
F. Domesticated animals so not eat a variety of foods.
G. Wild animals tend to benefit from recessive traits such as albinism.
H. Parents of wild animals usually reject offspring with recessive traits.
I. Domesticated animals are inbred and more likely to have recessive traits.
Base your answers to questions 5 and 6 on the diagram below. T and t represent
the alleles for the tall and dwarf traits, respectively.
?
? Tt
? Tt
?
tt
tt
5. What genotypic ratio is expected in the offspring of this cross?
a. 1 Tt : 1 tt
b. 3 Tt : 1 tt
c. 1 Tt : 3 tt
d. 1 TT : 1 tt
6. If this cross produced 240 offspring, how many of the offspring would be
expected to have the dwarf trait?
R. H. Beeman
Chapter 8 Mendel’s Genetics) Review
Biology I
Text pages 184, 185
page 4 of 4
ANSWERS
1.
2.
3.
4.
5.
6.
7.
b
b
b
a
c
c
d
8. A copy of the functional gene is attached to the DNA of a virus. The functional
gene gets into the defective cells by “piggybacking” on the virus. Once inside the
cells, it produces a functional protein that helps remedy the disease.
9. During meiosis II, the members of each pair of alleles separate when gametes
are formed as described in the law of segregation.
10. 1 YYRR : 2 YyRR : 1 yyRR
12. Patterns obtained from large samples are less likely to be distorted by rare
events that can occur by chance.
13. Cystic fibrosis is a recessive autosomal disorder. Thus, each parent must have
the recessive allele. Chances are increased that his sister is a carrier
(heterozygote) for cystic fibrosis.
1
2
3
4
5
6
A
I
D
I
A
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