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

O No, with fewer chromosomes than humans, the probablities woukl be diferent
© Yes, the probabillty of any outcome is independent ef prior outcomes
O No, the 50150 probablties mean that at least 50% of the offspring shoult be homozygous for long hair
• Yes, the difference in number of chromosomes would allow this to happen

Answer 1

The correct answer 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 cat (Ss) is mated with a homozygous long-haired cat (ss), the expected genetic outcomes for their offspring are as follows:

• 50% chance of Ss (heterozygous short hair)
• 50% chance of ss (homozygous long hair)

This means that, on average, out of 11 offspring, you would expect about 5.5 offspring to be heterozygous (short hair) and about 5.5 to be homozygous (long hair). However, since we cannot have half an individual, this would imply that if 11 offspring were born, it is statistically reasonable to expect that at least some (in fact, up to 6) of them could be homozygous for long hair (ss), not just all 11 being homozygous for long hair. Thus, having all 11 offspring with long hair (ss) is statistically improbable.