Question

If you had two guinea pigs of opposite sex, both homozygous, one black and one brown, but you didn't know which was the dominant characteristic, how would you find out the dominant colour?

Options

• Mate them together and see what colour the offspring are,that will be the dominant colour

• Mate them together and see what colour the offspring are,the other will be the dominant colour

• Mate them together, then mate their offspring to see what colour the grandchildren are,that will be the dominant colour

• Mate them together, then mate their offspring to see what colour the grandchildren are,the other colour will be the dominant colour

Answer 1

Mate them together and see what colour the offspring are,that will be the dominant colour

Explanation:

If you mate two homozygous guinea pigs of opposite sex, one black and one brown, the offspring will all show the dominant colour. This is because the dominant allele masks the expression of the recessive allele in heterozygous offspring. So, whichever colour appears in all the offspring is the dominant characteristic. Mating and observing the first generation offspring is enough; you do not need to look at the grandchildren to determine dominance in this case.