Question

If the gene for white eyes (W gene) is located on X chromosome

W= allele for red (Dominant)

w= allele for white

The parents are true breeding.

Prediction of Reciprocal crosses

1.) Red Female x White Male (show punnet square)

Genotype Proportion

Female:

Male:

Phenotype Proportion

Female:

Male:

2.) White Female x Red Male (show punnet square)

Genotype Proportion

Female:

Male:

Phenotype Proportion

Female:

Male:

Answer 1

1) Red female (X^W X^W) × White male (X^w Y)

Punnet square:

Gametes	X^w	Y
X^W	X^W X^w ( red female)	X^W Y ( red male)
X^W	X^W X^w ( red female)	X^W Y ( red male)

Genotype Proportion: 1:1

Female: X^W X^w (2)

Male: X^W Y (2)

Phenotype Proportion: All red (1)

Female: Red (2)

Male: Red (2)

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2) Whitefemale (X^w X^w) × Red male (X^W Y)

Punnet square:

Gametes	X^W	Y
X^w	X^W X^w ( red female)	X^w Y ( white male)
X^w	X^W X^w ( red female	X^w Y ( white male

Genotype Proportion: 1:1

Female: X^W X^w (2)

Male: X^w Y (2)

Phenotype Proportion: 1:1

Female: red (2)

Male: white (2)