Analysis help

Name:__________________ Date:_______

Punnett Square Practice Worksheet

1) For each of the genotypes (AA, Aa or aa) below determine what the phenotype would be.

Purple flowers are dominant to white flowers.

PP_____________ Pp____________ pp_______________

Hairy knuckles are dominant to non-hairy knuckles in humans.

HH_____________ Hh ___________ hh _________________

Bobtails in cats are recessive. Normal tails are dominant.

TT _____________ Tt _________ tt _____________

2) For each of the following write whether it is homozygous dominant, heterozygous or

homozygous recessive.

AA __________________ gg ______________________

Pp ___________________ Ii _______________________

tt____________________ TT ______________________

Use the following information for questions 3-5: In dogs, the gene for fur color has two alleles. The dominant allele (F) codes for grey fur and

the recessive allele (f) codes for black fur.

3) The female dog is heterozygous. The male dog is homozygous recessive. Figure out the

percentage or ratio of possible phenotypes and genotypes of their puppies by using a Punnett

Square.

% of possible Genotypes:

FF: ________

Ff: ________

ff: _________

% of possible Phenotypes:

Black fur: __________

Grey fur: ___________

_______ _______

_______

_______

Place the alleles for the male parent

below. One allele on each line:

Place the alleles for the

female parent on the

side. One allele on

each line:

Name:__________________ Date:_______

4) The female dog has black fur. The male dog has black fur. Figure out the phenotypes and

genotypes of their possible puppies by using a Punnett Square.

% of possible Genotypes:

FF: ________

Ff: ________

ff: _________

% of possible Phenotypes:

Black fur: __________

Grey fur: ___________

5) The female dog is heterozygous. The male dog is heterozygous. Figure out the phenotypes

and genotypes of their possible puppies by using a Punnett Square.

% of possible Genotypes:

FF: ________

Ff: ________

ff: _________

% of possible Phenotypes:

Black fur: __________

Grey fur: ___________

6) In fruit flies, red eyes are dominant (E). White eyes are recessive (e). If the female fly has

white eyes and the male fly has homozygous dominant red eyes, what are the possible

phenotypes and genotypes of their offspring?

Genotypes: Phenotypes:

EE: Red Eyes:

Ee:

ee: White Eyes:

_______ _______

_______

_______

_______ _______

_______

_______

Name:__________________ Date:_______

A Little added challenge

Use the following for questions 7-9: In dogs, there is a hereditary deafness caused by a recessive gene, “d.” A kennel owner

has a male dog (Gilbert) that she wants to use for breeding purposes if possible. The dog can

hear.

7) What are the two possible genotypes of Gilbert?

8) If the dog’s genotype is Dd, the owner does not wish to use him for breeding so that

the deafness gene will not be passed on. This can be tested by breeding the dog to a deaf female

(dd). Fill in these two Punnett squares to illustrate the crosses for your possible male genotypes

(from question 7) with the deaf female dog.

Possible Cross 1

Possible Cross 2

% of possible Genotypes:

DD: ________

Dd: ________

dd: _________

% of possible Phenotypes:

Deaf pups: ___________

Hearing pups: ________

% of possible Genotypes:

DD: ________

Dd: ________

dd: _________

% of possible Phenotypes:

Deaf pups: ___________

Hearing pups: _________

9) Explain how could you tell the genotype of Gilbert’s male dog?

_______ _______

_______

_______

_______ _______

_______

_______

Name:__________________ Date:_______

Use the following for questions 10-11:

Having a widow’s peak like Wentworth

Miller is dominant.

Not having a widow’s peak, like Rihanna, is

recessive.

10) If Wentworth Miller is Aa, and he and Rihanna had children, what are the possible

phenotypes and genotypes of their children?

11) Look at the phenotypes of Beyonce and

Jay Z. If these two had children, could they have

children with a widow’s peak? Why or why not? Use

a Punnett Square to explain your answer.