Genetics: Punnett Squares and Traits

The video tutorial explains hemophilia as an X-linked recessive trait, focusing on genetic inheritance patterns. It discusses the expected outcomes for offspring when one parent is a carrier. The tutorial uses a Punnett square to illustrate how traits are passed down, emphasizing that males are more likely to be affected due to their XY chromosome configuration. The video concludes by interpreting the genetic results, highlighting that female carriers have a 50% chance of passing the trait to their sons.

What is the genetic status of the father in the context of hemophilia?

• He is unaffected by the trait.

• He is affected by the trait.

• He has two X chromosomes.

• He is a carrier of the trait.

What does it mean for a trait to be X-linked recessive?

• It is recessive and located on the X chromosome.

• It is dominant and located on the Y chromosome.

• It is dominant and located on the X chromosome.

• It is recessive and located on the Y chromosome.

What is the purpose of creating a Punnett square in genetics?

• To determine the exact number of offspring.

• To predict the probability of inheriting specific traits.

• To identify the gender of offspring.

• To calculate the lifespan of offspring.

In a Punnett square, what do the two boxes representing males indicate?

• Both males will be unaffected.

• One male will be affected, and one will be unaffected.

• Both males will be carriers.

• Both males will be affected.

Why do females need two copies of the recessive allele to express an X-linked trait?

• Because they have two X chromosomes.

• Because they have one X and one Y chromosome.

• Because they have one X chromosome.

• Because they have two Y chromosomes.

What is the probability of a carrier mother passing the hemophilia trait to her son?

• 100%

• 25%

• 50%

• 75%

What is the likelihood of a daughter being a carrier if her mother is a carrier?

• 100%

• 0%

• 25%

• 50%

What is the genetic makeup of a female who is a carrier of hemophilia?

• XX with both X chromosomes having the trait.

• XY with the X chromosome having the trait.

• XY with no X chromosome having the trait.

• XX with one X chromosome having the trait.

What is the role of a carrier in the context of X-linked recessive traits?

• They express the trait.

• They have two copies of the dominant allele.

• They cannot pass the trait to offspring.

• They carry one copy of the recessive allele without expressing the trait.

What is the expected outcome for female offspring in terms of hemophilia?

• None will be affected, but some may be carriers.

• All will be carriers.

• All will be affected.

• Half will be affected.