Question

In Guinea pigs, short hair is dominant and long hair is recessive. A

heterozygous male is crossed with a long-haired female. They have a litter
of six babies. Answer the following: (a) What letters will you use for this
cross and what will they represent? (b) What is the parent cross? (c) What
are the possible genotypes of the offspring, and what percent will carry
each genotype? (d) If they have six babies, how many would you expect to
have long hair? short hair? *

Answer 1

a. S represents allele for short hair while s represents allele for long hair.

b. Ss (male) × ss (female)

c. 50% Ss, 50% ss

d. 3 long hair (ss), 3 short hair (Ss)

Step-by-step explanation:

This question involves a single gene coding for hair length in guinea pigs. The allele for short hair (S) is dominant over the allele for long hair (s).

a. Letter "S" will represent the allele for short hair while letter "s" will represent the allele for long hair.

b. According to this question, a heterozygous male is crossed with a long-haired female. The genotype of the male guinea pig is "Ss" while that of the female is "ss". (see attachment for the punnet square)

c. The possible genotypes of the offsprings in this cross are: Ss and ss, each carrying 50% each as they are produced in a ½ Ss: ½ ss.

d. Since 50% of the offsprings will be both short haired and long haired, If they have six babies, 3 of them will be short-haired while 3 of them will also be long-haired.