wayground logo

Free Printable Worksheets

NEW

Font size

S
M
L
XL
Worksheets

Genetics Review

Total questions: 40

Worksheet time: 43mins

Name
Class
Date
1.

The __________ allele is always expressed in an organism when it is present.

a)

dominant

b)

hybrid

c)

recessive

d)

heterozygous

2.

A genotype is

a)

the alleles an organism has for a certain gene

b)

the physical appearance of the trait

c)

a sperm or egg cell

d)

the letters seen on the outside of the Punnett square

3.

The different forms of a gene are called

a)

genotypes

b)

alleles

c)

hybrids

d)

traits

4.
Long tongues (T) are dominant to short tongues in green tree frogs.  What is the probability that two frogs that are heterozygous for long tongues could produce offspring with short tongues?
a)
100%
b)
75%
c)
50%
d)
25%
5.
In watermelons, green rinds (G) are dominant to striped rinds (g).  What is the genotype of a heterozygous green watermelon?
a)
GG
b)
Gg
c)
gg
d)
green
6.

The genotype of this flower is _____________

a)

red

b)

heterozygous

c)

homozygous dominant

d)

homozygous recessive

7.

The genotype of this flower is ______.

a)

homozygous dominant

b)

heterozygous

c)

pink

d)

homozygous recessive

8.
Round seeds (R) are dominant over wrinkled seeds (r). What percentage of the offspring will be round from the following cross?
Rr X Rr
a)
100%
b)
75%
c)
50%
d)
25%
9.
Round seeds (R) are dominant over wrinkled seeds (r). What percentage of the offspring will be round from the following cross?
RR X Rr
a)
100%
b)
75%
c)
50%
d)
25%
10.

A heterozygous round-seeded plant (Rr) is crossed with a homozygous dominant round-seeded plant (RR). What percentage of the offspring will be homozygous dominant?

a)

100%

b)

75%

c)

50%

d)

25%

11.
A homozygous round seeded plant is crossed with a homozygous wrinkled seeded plant. What percentage of the offspring will be homozygous recessive?
R = round
r = wrinkled
a)
75%
b)
50%
c)
25%
d)
0%
12.
In guinea pigs, the allele for short hair is dominant over the allele for long hair.
B = short 
b = long
What genotype would a homozygous recessive guinea pig have?
a)
BB
b)
bb
c)
Bb
13.

Smooth seeds are dominant over wrinkled seeds.

What is the genotype ratio of the offspring from the following cross?

Nn X NN

a)

NN = 100%, Nn = 0%, nn = 0%

b)

NN = 50%, Nn = 25%, nn = 25%

c)

NN = 50%, Nn = 50%, nn = 0%

d)

NN = 25%, Nn = 50%, nn = 25%

14.

G = green g = yellow

Cross two plants that are heterozygous for green pods.

What is the phenotype ratio of the offspring?

a)

25% green, 75% yellow

b)

25% green, 75% yellow

c)

50% green, 50% yellow

d)

75% green, 25% yellow

15.

What gamete possibilities could come from this parent's genotype?

a)

AB and aB

b)

Ab, AB, Ab, and ab

c)

Ab only

d)

AB, aB, and ab

16.

What gamete possibilities could come from this parent's genotype?

a)

aB, ab, AB, and Ab

b)

Ab and AB

c)

AA and bB

d)

AB only

17.

What goes in box 3?

a)

Aabb

b)

AABB

c)

AAbb

d)

aaBb

18.

What is the correct phenotype ratio when crossing two heterozygous parents in a dihybrid cross?

a)

100% heterozygous

b)

1:2:1

c)

3:1

d)

9:3:3:1

19.
What is the genotype for a pea plant heterozygous for round seeds (R), and homozygous recessive for green seeds (y)?
a)
Ry
b)
RRyy
c)
RrYy
d)
Rryy
20.
In guinea pigs, black hair is dominant to white hair and short hair is dominant to long hair. What would be the phenotype of a guinea pig with the genotype Bbss?
a)
Black hair, long hair
b)
Black hair, short hair
c)
White hair, long hair
d)
White hair, short hair
21.

What is the genotype ratio of the offspring from this cross?

a)

TT = 25% Tt= 50% tt=25%

b)

all tall

c)

TT= 75% tt = 25%

d)

Tt = 100%

22.

In pea plants tall is dominant (T) over short plants (t), and green is dominant (G) over yellow (g). Cross a tall green pea plant (TtGg) with a short yellow pea plant (ttgg). What is the phenotype ratio of the offspring?

a)

1: 2: 2: 1

b)

9: 3: 3: 1

c)

4: 4: 4: 4

d)

3: 3: 3: 3

23.
A male beetle has the genotype Ttbb. If this beetle mates with a female with genotype TTBb, what is the chance their offspring will have the genotype TtBb?
a)
3/16
b)
4/16
c)
8/16
d)
12/16
24.

A white mouse with red eyes is crossed with a black mouse with brown eyes. The white mouse is recessive for both of its traits. The black mouse is dominant for both of its traits.

This cross would be

a)

BBEE x bbee

b)

BBEe x BbEe

c)

BbEE x BbEe

d)

BBee x BBEE

25.

What goes in box 15?

a)

aabb

b)

AABB

c)

aaBB

d)

AAbb

26.

What ratio of the offspring from the cross shown will be homozygous recessive?

a)

0 in 4

b)

1 in 4

c)

2 in 4

d)

4 in 4

27.

How many alleles (letters) does each person carry for each gene?

a)

1

b)

2

c)

3

d)

4

28.

What is the phenotype ratio of the offspring from this cross? (Brown hair is dominant to blonde hair)

a)

50 % Brown Hair and 50% Blond Hair

b)

25 % Brown Hair and 75% Blond Hair

c)

75 % Brown Hair and 25% Blond Hair

d)

0% Brown Hair and 100% Blond Hair

29.

The phenotype of this flower is _____________

a)

red

b)

heterozygous

c)

homozygous dominant

d)

homozygous recessive

30.

What percent of this mother's eggs will have the dominant allele for BOTH genes?

a)

50%

b)

0%

c)

100%

d)

25%

31.

In a dihybrid cross, how many possible phenotypes appear in the offspring?

a)

2

b)

8

c)

4

d)

3

32.

In guinea pigs, black hair is dominant to white hair. You have a pet guinea pig with white hair. What genotype(s) COULD your guinea pig have?

a)

BB only

b)

BB or Bb

c)

bb only

33.

Your pet guinea pig Farfalle got pregnant and had pups! Farfalle has black hair, which you know is dominant to white hair. Farfalle had a play date 2 months ago with studly white-haired Couscous, so he must be the father, but ALL of Farfalle's pups have black hair. What is Farfalle's most likely genotype for the hair color gene?

a)

Heterozygous

b)

Homozygous dominant

c)

Homozygous recessive

34.

In a monohybrid cross, how many possible genotypes appear in the offspring?

a)

2

b)

8

c)

4

d)

3

35.

Which of Mendel's laws states that alleles are separated during gamete formation?

a)

Law of Dominance

b)

Law of Segregation

c)

Law of Independent Assortment

36.

Which of Mendel's laws states that alleles are distributed to gametes independently of one another?

a)

Law of Dominance

b)

Law of Segregation

c)

Law of Independent Assortment

37.

Which are correct examples of gametes?

a)

Skin cells and intestinal cells

b)

Egg cells and sperm cells

c)

Ovary cells and testicle cells

d)

Dominant cells and recessive cells

38.

Which of Mendel's laws does this statement demonstrate?:


If your genotype is Bb, then you can only pass a B or b to your child, but you can't pass both.

a)

Law of Dominance

b)

Law of Segregation

c)

Law of Independent Assortment

39.

Which of Mendel's laws does this statement demonstrate?:


Person A is smart and has brown hair while Person B is also smart and has blonde hair.

a)

Law of Dominance

b)

Law of Segregation

c)

Law of Independent Assortment

40.

Huntington’s disease is caused by a dominant allele. If a woman who is heterozygous for the trait marries a healthy man, what is the chance that their child will have the disease?

a)

0%

b)

50%

c)

75%

d)

100%