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Punnett Square Practice

Total questions: 40

Worksheet time: 2hrs 0mins

Name
Class
Date
1.

What you see, or the physical appearance.

a)

Genotype

b)

Phenotype

c)

Homozygous

d)

Heterozygous

2.

Aa, DD, Ba, and yy are all examples of ---

a)

genotypes

b)

phenotypes

3.

Which of the following is a phenotype?

a)

Aa

b)

red hair

c)

heterozygous

d)

DNA

4.

Which of the following genotypes is heterozygous?

a)

Bb

b)

BB

c)

bb

d)

B

5.

Which of the following is homozygous dominant?

a)

Yy

b)

Y

c)

yy

d)

YY

6.

What allele combination should go in the missing box?

Make a Punnett square to determine this

a)

AA

b)

Aa

c)

aa

d)

none of these

7.

T - tall and t = short
In the Punnett square below, what belongs in the missing square

Create a Punnett square to find the answer

a)

tt

b)

Tt

c)

Bb

d)

TT

8.

In a certain species of plant, the color purple (P) is dominant to the color white (p).
According to the Punnett Square, what is the probability of an offspring being purple?

a)

25%

b)

0%

c)

100%

d)

50%

9.

B = brown fur  b = white fur
In the punnett square, what is the probability for white fur? 

a)

0%

b)

25%

c)

50%

d)

75%

10.

What are the probabilities of the phenotype(s) of the offspring? (A-Brown hair; a-blond 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

11.

What is ratio of the offspring from the cross shown will be homozygous recessive for the trait of tallness? T = tall t = short

a)

0 in 4

b)

1 in 4

c)

2 in 4

d)

4 in 4

12.

In the punnett square shown, what must the genotype of the missing parent be?

a)

BB

b)

Bb

c)

bb

d)

Tt

13.

In a heterozygous genotype, the ___________ allele takes over in the phenotype.

a)

recessive

b)

dominant

c)

lower case letter

d)

both 

14.

The passing of traits from parents to offspring is called

a)

cloning

b)

heredity

c)

deoxyribonucleic acid, or DNA

d)

precipitation

15.

In the Punnett square shown, what must the genotype of the missing parent be?

Create a Punnett square to determine this

a)

BB

b)

Bb

c)

bb

d)

Tt

16.

B = brown fur  b = white fur
In the Punnett square, what is the probability for white fur

a)

0%

b)

25%

c)

50%

d)

75%

17.

What are the possible genotypes for this cross?

Create Punnett square to determine this

a)

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

b)

all tall

c)

TT= 75% tt = 25%

d)

Tt = 100%

18.

What is the dominant trait?

a)

yellow pea seeds

b)

green pea seeds

c)

there is no dominant seed

d)

Jolly green giant

19.

What genotype would go in box 3?

Create a Punnett square to determine this

a)

BB

b)

Bb

c)

bb

20.

What genotype would go in box 1?

a)

BB

b)

Bb

c)

bb

21.

What genotype would go in box 2?

a)

BB

b)

Bb

c)

bb

22.

What is the probability of heterozygous offspring?

a)

0%

b)

100%

c)

50%

d)

25%

23.

If T=tall and t=short

What is the ratio for short phenotype in this cross?

Create a Punnett square to determine this

a)

0:4

b)

1:3

c)

2:4

d)

3:4

24.

Two brown eyed parents (Bb) have a baby. What is the chance the baby is blue eyed?

Cross them using a Punnett square to get your answers

a)

0 %

b)

25%

c)

50%

d)

75%

25.

What genotype would go in box 1?

Create a Punnett square to determine this

a)

BB

b)

Bb

c)

bb

26.

In a certain species of plant, the color purple (P) is dominant to the color white (p).

According to the Punnett Square, what is the probability of an offspring being purple?

a)

25%

b)

0%

c)

100%

d)

50%

27.

Which of these Punnett squares represents a cross between a homozygous dominant parent and a heterozygous parent?

a)
b)
c)
d)
28.

A dog with straight fur (Bb) is crossed with a dog with curly fur (bb). What is the probability the offspring will have straight fur?

Create a Punnett square to get the answer

a)

0%

b)

25%

c)

50%

d)

75%

e)

100%

29.

 In tomatoes, red fruit (R) is dominant over yellow fruit (r). A plant that is homozygous for red fruit is crossed with a plant that has yellow fruit.

Cross a homozygous dominant plant with a homozygous recessive plant

What is the ratio of red to yellow

a)

4:0

b)

0:4

c)

2:2

d)

1:2:1

30.

What is the phenotype of the heterozygous parent in the punnett square?

a)

green

b)

yellow

c)

hybrid

d)

purebred

31.

B = brown eyes
b = blue eyes
What is true about these two brothers that have brown eyes?
One has genotype BB the other Bb.

a)

they have same phenotype and genotype

b)

they have different genotypes and phenotypes

c)

they have same phenotype but different genotypes

d)

they have same genotype but different phenotypes

32.

What are the possible genotypes for this cross?
(Click the picture to see it without the text)

a)

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

b)

all tall

c)

TT= 75% tt = 25%

d)

Tt = 100%

33.

What is the genotypic ratio of the offspring?

a)

3:1

b)

1:3

c)

1:2:1

d)

2:2

34.

Who is considered the "father of genetics"?


HINT we called everything we have learned "Mendelian genetics"

a)

Reginald Punnett

b)

Gregor Mendel

c)

James Watson

d)

Charles Darwin

35.

What are the phenotype percentages of the offspring?

(A-Brown fur color; a-white fur color)

a)

50 % Brown fur and 50% White fur

b)

25 % Brown fur and 75% White fur

c)

75 % Brown fur and 25% White fur

d)

0% Brown fur and 100% White fur

36.

One guinea pig is heterozygous for short hair (Ss) and one is homozygous recessive for long hair (ss). Create a Punnett square and determine what PERCENT is homozygous?

a)

0%

b)

25%

c)

50%

d)

100%

e)

75%

37.

One guinea pig is heterozygous for short hair (Ss) and one is homozygous recessive for long hair (ss). Create a Punnett square and determine what PERCENT would have LONG hair?

a)

0%

b)

25%

c)

50%

d)

100%

e)

75%

38.

 In humans, being a tongue roller (R) is dominant over non-roller (r). A man who is a non-roller

marries a woman who is heterozygous for tongue rolling.

Cross 2 heterozygous individuals who can roll their tongue

What is the ratio of genotypes?

a)

1:2:1

b)

2:2

c)

0:4

d)

1:3

39.

 In humans, being a tongue roller (R) is dominant over non-roller (r).

Cross 2 heterozygous individuals who can roll their tongue

What percent of kids would be tongue rollers?

a)

0%

b)

25%

c)

50%

d)

75%

e)

100%

40.
How many boxes would say BB?
a)
1
b)
2
c)
4
d)
0