Question

In rabbits, short hair(S) is dominant over long hair(s). What genotype and phenotype ratios are expected from a cross between two heterozygous shorthaired rabbits?

Answer 1

Answer:

Explanation:

Among rabbits, short hair is dominant over long hair. What would be the appearance of the

rabbits if a heterozygous short hair female were mated with a homozygous short hair male?

Answer 2

Answer:

Genotype                  Phenotype                      

SS                 1/4          Short hair         3/4

Ss                 2/4         Short hair          3/4

ss                  1/4          Long hair          1/4

Explanation:

Both are heterozygous for the trait so we can expect that the cross would be:

Ss x Ss

    S     s

S  SS   Ss

s   Ss   ss

So the resulting off-spring would have the following genotype and phenotype:

1 out of 4 will have a genotype of SS.

2 out of 4 or half will have a genotype of Ss.

1 out of 4 will have a genotype of ss.

But because short hair is dominant the phenotype ratios would differ because Ss and SS would express short hair, so we add up their ration:

Short hair: 1/4 + 2/4 = 3/4

Long hair:  1/4

So in summary:

Genotype                  Phenotype                      

SS                 1/4          Short hair         3/4

Ss                 2/4         Short hair        

ss                  1/4          Long hair          1/4