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Genetics Study Guide



Multiple Choice
Identify the choice that best completes the statement or answers the question.
 

 1. 

DNA is found in ____ cells.
a.
sex
c.
all
b.
sperm
d.
no
 

 2. 

A ____ is part of the DNA code on a chromosome.
a.
gene
c.
phenotype
b.
genotype
d.
gender
 

 3. 

The study of ____ is called genetics.
a.
heredity
c.
pea plants
b.
dominance
d.
mutations
 

 4. 

Gregor Mendel studied heredity using ____ plants.
a.
rose
c.
maize
b.
pea
d.
tundra
 

 5. 

Gregor Mendel concluded that a parent passes ____ of the alleles for a trait to their offspring.
a.
two
c.
one
b.
three
d.
four
 

 6. 

Mendel developed the principle of independent ____ to understand how traits are passed through generations.
a.
generations
c.
breeding
b.
heredity
d.
assortment
 

 7. 

A Punnett square shows you all the ways in which ____ can combine.
a.
alleles
c.
sperm
b.
eggs
d.
colors
 

 8. 

Blood type in humans is controlled by ____ alleles.
a.
one
c.
three
b.
two
d.
four
 

 9. 

Mendel called plants that received different alleles for a trait from each parent ____.
a.
hybrids
c.
genotypes
b.
dominant
d.
phenotypes
 

 10. 

In a Punnett square, a capital letter stands for a ____ allele.
a.
recessive
c.
homozygous
b.
dominant
d.
heterozygous
 

 11. 

Of the following, which is NOT a human blood phenotype?
a.
O
c.
B
b.
AB
d.
C
 

 12. 

Of the following, which represents a homozygous recessive genotype?
a.
TT
c.
tt
b.
Tt
d.
TTT
 

 13. 

Physical characteristics of an organism are ____.
a.
alleles
c.
genes
b.
traits
d.
recessive
 

 14. 

____ is the study of how traits are passed from parents to offspring.
a.
Fertilization
c.
Seed production
b.
Genetics
d.
Selective breeding
 

 15. 

Each gene of a gene pair is an ____.
a.
identical match
c.
error
b.
offspring
d.
allele
 
 
nar001-1.jpg
Figure 6
 

 16. 

Refer to Figure 6. A heterozygous orange-flowered plant is crossed with a homozygous purple-flowered plant. If orange is a dominant allele and purple is recessive, what color ratio will the flowers of the offspring plants have?
a.
1 purple: 3 orange
b.
4 purple: 0 orange
c.
2 purple: 2 orange
d.
0 purple: 4 orange
 
 
nar002-1.jpg
Figure 8
 

 17. 

Refer to Figure 8. In this cross between two pea plants, the offspring are:
a.
100% smooth.
b.
50% smooth and 50% wrinkled.
c.
75% wrinkled and 25% smooth.
d.
75% smooth and 25% wrinkled.
 

 18. 

Refer to Figure 8. In this cross between two pea plants,
a.
one of the parents has green seeds, and one has yellow seeds.
b.
both of the parents have smooth seeds.
c.
one of the parents has smooth seeds, and one has wrinkled seeds.
d.
both of the parents have yellow seeds.
 
 
nar003-1.jpg
Figure 13
 

 19. 

Refer to Figure 13. Bird A has the genotype ll for bill length, and Bird B is LL. The bills of their offspring would be:
a.
long in 100% of the offspring.
b.
short in 100% of the offspring.
c.
long in 50% of the offspring.
d.
short in 75% of the offspring.
 

 20. 

Kari has two pet rats with black fur. When her rats mated, one of their four offspring had white fur, and the other three had black fur. Which is most likely true for Kari’s rats?
a.
Both parents are homozygous for the white-fur trait, which is recessive.
b.
Both parents are heterozygous for the white-fur trait, which is dominant.
c.
Both parents are heterozygous for the white-fur trait, which is recessive.
d.
Both parents are heterozygous for the white-fur trait, which is sex-linked.
 
 
nar004-1.jpg
Figure 14
 

 21. 

Refer to Figure 14. If a Type A and Type B couple produce offspring, the offspring can be:
a.
Type A or Type B only
b.
Type O only
c.
Type A, B, AB, or O
d.
Type AB only
 

 22. 

Refer to Figure 14. If a Type A and Type B couple produce offspring, the offspring can be:
a.
IAi, IBi, or ii
b.
IBi or ii
c.
IAIB, IAi, IBi, or ii
d.
IAIA, IAi, IBi, or ii
 
 
nar005-1.jpg
Figure 9
 

 23. 

Refer to Figure 9. Some members of this family have a certain trait. The chart shows that:
a.
both parents are heterozygous for the trait.
b.
the trait is caused by a dominant allele.
c.
a fatal illness results from the trait.
d.
the trait occurs only in males.
 
 
nar006-1.jpg
Figure 10
 

 24. 

Refer to Figure 10. Some members of this family have a certain trait. The female represented by the label A
a.
has the trait.
b.
carries the trait.
c.
is homozygous dominant for the trait.
d.
is homozygous recessive for the trait.
 
 
nar007-1.jpg
Figure 11
 

 25. 

Refer to Figure 11. A man and a woman want to have a child, but the man is heterozygous (Cc) for a recessive trait that causes a fatal illness. What is the probability of a child’s inheriting the trait?
a.
50%
b.
25%
c.
0%
d.
75%
 

Matching
 
 
Match each statement with the correct item below.
a.
organisms with two different alleles for a trait
b.
when an intermediate form is expressed in offspring
c.
when more than two alleles control a trait
d.
physical appearance of an organism
e.
helps determine the chance that something will occur
f.
when a group of gene pairs act together
g.
genetic makeup of an organism
h.
tool for tracing a trait through a family
 

 26. 

pedigree
 

 27. 

heterozygous
 

 28. 

genotype
 

 29. 

phenotype
 

 30. 

probability
 

 31. 

incomplete dominance
 

 32. 

multiple alleles
 
 
Match each statement with the correct item below.
a.
organism that always produces the same traits in its offspring
b.
a factor that seems to disappear
c.
when there are two alleles that are exactly the same
d.
a factor that covers up another factor
e.
the different forms a gene has for a trait
f.
passing on of traits from parents to offspring
g.
study of heredity
 

 33. 

purebred
 

 34. 

homozygous
 

 35. 

heredity
 

 36. 

dominant factor
 

 37. 

recessive factor
 

 38. 

allele
 

 39. 

genetics
 

Completion
Complete each statement.
 

 40. 

A yellow pea plant crossed with a homozygous green pea plant produces the following offspring: yellow, yellow, green, green. The yellow pea plant's genotype would be _______________ for color.
 

 

 41. 

A human baby has two X chromosomes. Its sex is _______________.
 

 

 42. 

An organism that always produces the same traits in its offspring is a(n) _______________.
 

 

 43. 

Purebred dogs often show variations in coat color. This is an example of _______________ dominance in genetics.
 

 

 44. 

An organism's genetic makeup is called its ____________________.
 

 

 45. 

Passing of traits from parents to offspring is ____________________.
 

 

 46. 

A ____________________ square is a model that helps make genetic predictions.
 

 

 47. 

A(n) ____________________ is a visual tool for following a trait through generations of a family.
 

 



 
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