Biology Hour____ Name___________________________________________
Dr. Wexler
Heredity Worksheet 2
Monday 3/2/09
Due Tuesday 3/3/09

1) In sheep fur, white is due to a dominant factor (W) while black is due to a recessive gene (w).

A white ewe mated with a white ram and produced a black lamb.

What are the chances that the next offspring would be white? Show your work using a Punnett square.

2) A blue-eyed man, whose parents were brown eyed, marries a brown-eyed woman

whose father was brown-eyed and whose mother was blue eyed. They have one child

who is blue eyed.

What are the genotypes of all the individuals mentioned? Show/explain your work/reasoning

Considering the limited information you still should be able to determine everyone's genotype. If there can be more than one genotype for an individual, list them.

A. blue-eyed man:

B. brown-eyed parents:

C. brown-eyed woman:

D. brown-eyed father:

E. blue-eyed mother:

F. blue-eyed child:

3) In mice, the genotype yy is gray; Yy is yellow; and YY dies as a small embryo.

A. What offspring would be expected from a cross between a yellow and a gray? Show your work using a Punnett square.

B. What offspring would be expected from a cross between a yellow and a yellow? Show your work using a Punnett square.

C. What cross would yield the largest size litter? Why?