Question

In goats, the gene for coat color is on an autosome, and light brown color is dominant to black. A light brown male is mated to a black female, producing a black kid (baby goat). If they produce another kid, could it be light brown? If so, what are the chances of it being light brown?

A. Yes, but it will depend on whether the kid is male or female
B. Yes, 100% since the first kid was black, the next one has to be light brown
C. Yes, 75% since light brown is dominant
D. No, since the black allele is present, all offspring will be black
E. Yes, 50% as the male must be heterozygous for color

Answer 1

The male goat must be heterozygous for coat color since he produced a black offspring with a black female. Therefore, there is a 50% chance of any subsequent kids being light brown, regardless of sex, as this is an autosomal trait.

Step-by-step explanation:

Yes, the next kid could be light brown, and the chances are 50% since the male must be heterozygous, as indicated by the birth of a black offspring.Since the male goat is light brown and the female is black, it was presumed that the male was homozygous dominant for the coat color. However, the birth of a black kid disproves this, revealing that the male must actually be heterozygous (carrying one dominant and one recessive allele). Given Mendelian genetics, when a heterozygous light brown goat (Bb) is mated with a homozygous black goat (bb), the expected phenotypic ratio of the offspring is 50% light brown and 50% black.

This is because in each pregnancy, there's a 50% chance that the kid will inherit the dominant B allele from the father, resulting in a light brown coat, and a 50% chance it will inherit a recessive b allele from both parents, resulting in a black coat. The sex of the offspring is not a factor in this expression of coat color, as the gene for coat color is located on an autosome, not a sex chromosome.