Understanding Hemophilia and Punnett Squares

The video explains why hemophilia is more common in males than females using Punnett squares. Hemophilia is a recessive x-linked trait, meaning females can be carriers without showing symptoms, while males with the trait express the disease. The video demonstrates how to use Punnett squares to predict genetic outcomes and explains the probability of inheriting hemophilia based on parental genetics.

What type of genetic trait is hemophilia?

• Recessive Y-linked

• Dominant Y-linked

• Recessive X-linked

• Dominant X-linked

How can a female be a carrier of hemophilia?

• By having one dominant and one recessive allele

• By having two dominant alleles

• By having a Y chromosome

• By having two recessive alleles

In a Punnett square for an X-linked trait, what does the Y chromosome contribute?

• A dominant allele

• Nothing

• Both dominant and recessive alleles

• A recessive allele

What is the probability of a male having hemophilia if his mother is a carrier and his father is unaffected?

• 100%

• 0%

• 50%

• 25%

In a scenario where both parents have hemophilia, what is the probability of their daughter having the disease?

• 50%

• 100%

• 0%

• 25%

What is the chance of a female being a carrier if her father has hemophilia and her mother is unaffected?

• 50%

• 25%

• 100%

• 0%

If a female is a carrier and the father is unaffected, what is the probability of their son having hemophilia?

• 25%

• 100%

• 50%

• 0%

What genetic combination results in a female having hemophilia?

• Two recessive alleles

• One dominant and one recessive allele

• Two dominant alleles

• One recessive allele and a Y chromosome

What is the probability of a male being unaffected if his mother is a carrier and his father is unaffected?

• 25%

• 0%

• 100%

• 50%

Why is hemophilia more common in males than females?

• Males have two X chromosomes

• Females have a protective Y chromosome

• Males have only one X chromosome

• Females are more likely to be carriers