Question

cross a carrier female with a colorblind male. what is the genotype ratio of the offspring?
○ 1 xnxn: 1 xnxn: 1 xny: 1xny
○ 1 xnxn: 1 xnxn: 1 xny: 1 xny
○ 2 xnxn: 2 xny
○ 2 xnxn: 2 xny

Explanation:

Step1: Define parental genotypes

Carrier female: $X^N X^n$; Colorblind male: $X^n Y$

Step2: Set up Punnett square

	$X^N$	$X^n$
$Y$	$X^N Y$	$X^n Y$

Step3: Count offspring genotypes

Each genotype appears once in the 4 possible outcomes.

Answer:

1 XNXn: 1 XnXn: 1 XNY: 1XnY