Question

A black, short-haired cat has a litter of kittens with an orange, long-haired cat. The litter is entirely long-haired with mottled black and orange fur. What must be the inheritance pattern for each trait?

	a.	Short hair is dominant to long hair, and color shows incomplete dominance.
	b.	Short hair is dominant to long hair, and color shows codominance.
	c.	Long hair is dominant to short hair, and color shows incomplete dominance.
	d.	Long hair is dominant to short hair, and color shows codominance.

Answer 1

The correct answer for this question will be option D (Long hair is dominant to short hair, and color shows codominance).

Since the mother cat is black colored with short hairs, the development of long hair in the kittens concludes that long hair is dominant to short hairs thats why it expressed itself in the kittens (Hh) rather than in mother (hh) (H = dominant hair length; h = recessive hair length such that HH = long hair, Hh = long hair, and hh = short hair).

Further, color is expressing codominance since both colors are expressing themselves in the kittens. If it was incomplete dominance then color would have been a mixture of color. For example: assume parents with the red coat and white coat. If offspring are having patches of both color it is codominance i.e. both colors are expressing themselves and if the offsprings had pink coat then it is an example of incomplete dominance as none of the color completely dominated.