Chapter 3 Genetics: The Science of Heredity
Name: ___________________, ____________________
Date: ____________________ Period: ________
Multiple Choice: Chose the correct answer
I. The different forms of a gene are called
A. Alleles
B. Chromosomes
C. Phenotypes
D. Genotypes
II. In a coin toss, the probability of a coin landing heads up is
A. 100 percent
B. 75 percent
C. 50 percent
D. 25 percent
III. An organism with two identical alleles for a trait is
A. Heterozygous
B. Homozygous
C. Recessive
D. Dominant
IV. If the body cells of an organism have 10 chromosomes, then its sex cells would
have
A. 5 chromosomes
B. 10 chromosomes
C. 15 chromosomes
D. 20 chromos0mes
V. During protein synthesis, messenger RNA
A. “Reads” each three-letter code of bases
B. Releases the complete protein chain
C. Copies information from DNA in the nucleus
D. Carries amino acids to the ribosome
True of False
If the statement is true, write true. If it is false, change the underline word or words to
make the statement true
VI. ____________The scientific study of heredity is called genetics
VII. ____________An organism’s physical appearance is its genotype.
VIII. ____________In co-dominance, neither of the alleles is dominant or recessive.
IX. ____________ Heredity is the process by which sex cells form.
X. ____________Proteins are made in the nucleus of the cells
Checking Concepts: Students when you press the enter key press the backspace bar
to keep the numbering sequential (in chronological order)
XI. Describe what happens when Mendel crossed purebred tall pea plants with
purebred short plants.
XII. You toss a coin five times and it lands heads up each time. What is the
probability that it will land heads up on the six toss?
XIII. In guinea pigs, the allele for black fur (B) is dominated over the white fur (b). In
a cross between a heterogynous black guinea pig (Bb) and a white guinea pit (bb)
what is the probability that an offspring will have white fur? Use a punnett square
to answer the question.
XIV. In your own words, describe the sequence of steps in the process of Mitosis
XV. Describe the role of transfer RNA in protein synthesis.
XVI. Writing to Learn:
Imagine that you are a student in the 1860s visiting Gregor Mendel in his garden. Write a
letter to a friend describing Mendel/s experiment
Thinking Critically:
XVII. Applying Concepts:
In rabbits, the allele for a spotted coat is dominant over the allele for a solid-colored coat.
A spotted rabbit was crossed with a solid-colored rabbit. The offspring all had spotted
coats. What were the genotypes of the parents? Explain.
XVIII. Problem solving
Suppose you are growing purebred green-skinned watermelons. One day you find a
mutant striped watermelon. You cross the striped watermelon with a purebred green
watermelon. Fifty percent of the offspring are striped, while fifty percent are green. Is
the allele for the striped trait dominant or recessive? Explain.
XIX. Predicting
A new mutation in mice causes the coat to be twice as thick as normal. In what
environments would this mutation be helpful?
Applying skills
In peas, the allele for green pods (G) is dominant over the allele for yellow pods (g). The
table below the phenotypes of the offspring produced from a cross of two plants with
green pods. Use the data to answer Questions 20-22.
Phenotype
Number of Offspring
Green pods
9
Yellow pods
3
XX. Calculating:
Calculate what percent of the offspring have green pods? Calculate what percent have
yellow pods
XXI. Inferring
What is the genotype of the offspring with yellow pods? What are the possible genotypes
of the offspring with green pods?
Chapter 4 Modern Genetics
Comparing and Contrasting:
How are selective breeding and genetic engineering different? How are they similar?
(See question 22 on page 142)
Applying Skills: Chapter 4 Modern Genetics Pages 142-143
Use the information below to answer questions 23-29
Bob and Helen have three children.
Bob and Helen have one son who has albinism,
an inherited condition in which the skin does not
have brown pigments.
Neither Bob nor Helen has albinism.
Albinism is neither sex-linked nor co-dominant.
Interpreting Data:
Use the information to construct a pedigree. If you don’t know whether someone is a
carrier, leave their symbol empty. If you decide later that a person is a carrier, change
your pedigree.
Drawing Conclusions:
Is albinism controlled by dominant allele or by a recessive allele? Explain your answer.
Predicting:
Suppose Bob and Helen were to have another child. What is the probability that the child
will have albinism? Explain.
Thinking Critically Chapter 4 page 142
Applying Concepts:
Why can a person be a carrier of a trait caused by a recessive allele but not of a trait
caused by a dominant allele?
Problem Solving:
A woman with normal color vision has a colorblind daughter. What are the genotypes
and phenotypes both parent?
Calculating:
If a mother is a carrier of hemophilia, what is the probability that her son will have the
trait? Explain your answer/
Inferring:
How could ancient people selectively breed corn if they didn’t know about genes and
inheritance?
Comparing and Contrasting:
How are selective breeding and genetic engineering different? How are the similar?
Test Preparation: Use these questions to prepare for standardized tests.
Use the information to answer Questions 26-29
The Punnett square below shows how
muscular dystrophy, a sex-linked recessive
disorder, is inherited.
Father (normal)
XMY
Key
XM = normal
Allele
Xm = muscular
dystrophy
allele
Mother
XM Xm
(Carrier)
XM
Y
XMXM
XMY
XMXm
XmY
XM
Xm
26. What is the probability that a
daughter of these parents will
have muscular dystrophy?
A. 0% b 25% c.50% d 100%
27. What is the probability that a son of these
Parents will have muscular dystrophy?
A. 0% b 25% c.50% d 100%
28. What is the probability that a daughter of these
parents will be a carrier of the disease?
A. 0% b 25% c.50% d 100%
29. Which of the following statements is true of
Muscular dystrophy?
a. More men than women have muscular
dystrophy
b. More women than men have muscular
Dystrophy.
c. More men that women are carriers of
muscular dystrophy.
d. No women can have muscular dystrophy.