Cats have 38 chromosomes, or 19 pairs. Long hair in cats is a recessive trait (s) while short hair is a dominant trait (S). A cat that is heterozygous for short hair (Ss) and a cat that is homozygous for long hair (ss) are a mated pair. There is a 50% chance of an offspring being heterozygous for short hair, and a 50% chance of an offspring being homozygous for long hair. They have a total of 11 offspring, all of which have long hair. Is this possible? Why or why not?(1 point)

Question

Responses

No, the 50/50 probabilities mean that at least 50% of the offspring should be homozygous for long hair.
No, the 50/50 probabilities mean that at least 50% of the offspring should be homozygous for long hair.

Yes, the probability of any outcome is independent of prior outcomes
Yes, the probability of any outcome is independent of prior outcomes

No, with fewer chromosomes than humans, the probabilities would be different.
No, with fewer chromosomes than humans, the probabilities would be different.

Yes, the difference in number of chromosomes would allow this to happen.

Answer 1

The correct response is:

No, the 50/50 probabilities mean that at least 50% of the offspring should be homozygous for long hair.

Here's the reasoning:

When a heterozygous short-haired cat (Ss) is mated with a homozygous long-haired cat (ss), the possible genetic combinations for the offspring are as follows:

• From the Ss parent: S or s
• From the ss parent: s

This results in the following offspring genotypes:

1. Ss (short hair)
2. ss (long hair)

The expected genotypic ratio is 50% Ss (short hair) and 50% ss (long hair). Given that they have 11 offspring, statistically, you would expect about 50% of them (which would be approximately 5.5, but since you can't have half a cat, it's expected you would see at least some of each genotype in a larger sample size like this). Thus, if all 11 offspring have long hair, that contradicts the expected probabilities, making it statistically unlikely.