Heliconius melpomene is a species of butterfly with ZW sex d

Heliconius melpomene is a species of butterfly with ZW sex determination. H. melpomene\'s wing spots are normally orange, but a recessive Z-linked mutation causes the spots to be yellow, while a recessive autosomal mutation causes the spots to be red. Butterflies homozygous (or hemizygous) for both mutations have no wing spots. What are the expected F1 and F2 phenotypes from a cross between a red-spotted female and a yellow-spotted male?

Solution

F1

Z

w

Z

ZZ (no spot)

Zw(yellow)

W

Wz(red)

Ww(no spot)

So,

There will be one red spotted, one yellow spotted and 2 butterfly with no spot will be seen in F1 phenotypes

F2 gamates are