Question

Imagine that mermaids are real (yay!) and can either have large scaled tails (L, dominant) or small scaled tails (l, recessive). They have sex chromosomes like humans.

An XX mermaid is a carrier for small scaled tails.

An XY mermaid has a small scaled tail.

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1) If scale size was an autosomal mendelian trait

a) What are the two mermaid's genotypes? (1pt)

b) what percentage of their offspring would have large scaled tails? (1.5pts)

2) If scale size was an X-linked trait

a) What are the two mermaid's genotypes? (1pt)

b) what percentage of their offspring would have large scaled tails?

Answer 1

Note- When we say someone is a carrier for a trait, we mean that he/she is phenotypically normal (in this case, large scaled), but carries an allele for that trait (in this case, small scaled allele). Thus, the organism is heterozygous for the trait.

Thanks