Question

11. Punnett squares can also be used to predict genotypes of the parents. A guinea pig with short hair is crossed

to one that has long hair. Over a period of years, a scientist keeps records of the offspring and finds that 44 of
them have curly hair and 46 of them have straight hair. Based on this data, what are the genotypes of the parents:
х
Show the Punnett square of this cross to explain your reasoning.

Answer 1

Ss × ss

Step-by-step explanation:

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

According to this question, a guinea pig with short hair (S_) is crossed to one that has long hair (ss) to produce offsprings that have 44 short hair and 46 long hair. This number of offsprings produced indicate a ratio of 1:1, which can only be produced if the short haired guinea pig is heterozygous i.e. Ss.

Therefore, the genotype of the parents are Ss (short hair) and ss (long hair) i.e. Ss × ss. This combination will produce offsprings with the following proportion: Ss (1) : ss (1).