Question

Problem #1

Some mice have either a kinked tail or a normal tail. Kinked tails (K) are dominant. Located on

another chromosome is the gene for growth. This gene can either be dominant, causing

normal growth (N). or it can be recessive (n), causing obesity in the mouse. Two mice that are

heterozygous for a kinked tail and heterozygous for normal growth are crossed. What is the

phenotype ratio resulting from this cross?

P

Х

Answer 1

9/16 Kinked tail, normal growth

3/16 Kinked tail, obese growth

3/16 normal tail, normal growth

1/16 normal tail, obese growth

Step-by-step explanation:

Kinked tail (K) is dominant over normal tail (k) and normal growth (N) is dominant over obese growth (n). Two mice that are heterozygous for both traits (KkNn) are crossed:

KkNn x KkNn

offspring:

9/16 K_N_ - Kinked tail, normal growth

3/16 K_nn - Kinked tail, obese growth

3/16 kkN_ - normal tail, normal growth

1/16 kknn - normal tail, obese growth

(See the attached image for the Punnet's square analysis)