Question

Coat color in cats is partially determined by the X-linked O locus.  OO females and OY males are orange, while oo females and oY males are black.  Oo females are a mosaic of orange and black (calico cats). In a population of cats where this locus is at Hardy-Weinberg equilibrium, 4% of males are orange.

a) What is the frequency of the o (black) allele in the population?  ____________

b) What is the expected frequency of calico cats in this population, assuming equal numbers of males and females in the population?  ____________

Enter numeric answers to 4 decimal places (e.g., 50% is 0.5, 1/16 is 0.0625, 0.66666 is 0.6667).

You adopt a calico cat and find out that it is a male. What is its genotype?

	(a)	XOXo
	(b)	XOY
	(c)	XOXoY
	(d)	XOO

You investigate and learn that its mother was an orange cat and its father was a black cat. Which parent contributed the aneuploid gamete?

	(a)	The mother
	(b)	The father

In which meiotic division did the nondisjunction occur?

	(a)	Meiosis I
	(b)	Meiosis II

Answer 1

A) 4% males are orange means OY geneotype frequency is 0.04 , ie p = 0.04 Thus q= 0.96, ie oY are 96% males. Frequency of black allele is 0.96

B) calico cats frequency = 2pq = 2×0.04×0.96 = 0.0768

MCQ-

1) answer is C ) because male must have both O and o which are only present of X chromosome not on Y , so they must have 2 X and one Y for being calico

2) b) father caused aneuploidy because o Loci can only come from father as father was black and mother orange

3) answer is b) in meiosis 2

Please HIT THUMBSUPNIF I could help.