In the frog Rana rugosa yellow skin Xw is recessive to the w

In the frog (Rana rugosa), yellow skin (Xw) is recessive to the wildtype green skin (X+) and is an X-linked phenotype. A yellow male crossed with a homozygous green female. What is the expected phenotypic ratio?

1. 1 green male : 1 green female

2. 1 yellow female : 1 green male

3. 1 yellow male: 1 yellow female

4. 1 yellow male: 1 yellow female : 3 green male : 3 green female

5. 1 yellow male: 1 yellow female : 1 green male : 1 green female

Solution

As the phenotype is X linked, the pattern should be

Let\'s assume yellow skin - y and green skin - G for simplicity

So X^yY × X^gX^g

2X^yX^g, 2X^gY

So it goes as two green female and 2 green male which can also be written as one green male and one green female.

S option A is the correct answer.