Answer to Question #330450 in Genetics for Escape crew

Question

1. Merpeople can be found if you visit Black Lake on the grounds of Hogwarts. Tail colour in merpeople exhibits incomplete dominance. Red tails and white tails are both homozygous traits.

1. Indicate the genotypes for white tails and red tails. (2 marks)
2. What would a mermaid’s tail look like if she was heterozygous for red and white alleles? (1 mark)
3. Use a Punnett square to illustrate the cross between a merman with a white tail and a mermaid that is heterozygous for tail colour. Indicate the phenotypic ratio for their offspring. (3 marks)

Answer 1

Let A be the gene that is responsible for the color of the tails. Suppose that the genotype AA is responsible for red tails, and aa is responsible for white ones.

In the case of incomplete dominance of gene A, heterozygotes will have light red tails.

The cross between a merman with a white tail and a mermaid that is heterozygous for tail colour would look like this: