Several black guinea pigs of the same genotype were mated an

Several black guinea pigs of the same genotype were mated and produced 29 black offspring and 9 white offspring. What would you predict the genotypes of the parents to be? show work with punnet square if needed

Solution

Black guinea pigs were mated; which gave white offsprings along with black. This means the guinea pigs are heterozygous with black being the dominant trait.

Let the symbol for black be \'B\' and that for white be \'b\'.

The cross is: Bb X Bb

Result will be Black: white in 3:1

Here, the result is 29/38 = 0.76 (black) and 9/38 = 0.24 (white) i.e. 3:1

So, the genotypes of the parents was Bb