Question

Which statement about inheritance is true?

Girls get most of their traits from their moms; boys get most of their traits from their dads.
Male offspring will always have an X-linked genetic disease if the mom is a carrier.
Fathers always determine the gender of the offspring in humans.
Males never have Y chromosomes.

Answer 1

The correct answer is the third statement.

Step-by-step explanation:

In humans, the males possess one X and one Y chromosome, while the females possess two X chromosomes. Thus, the female always donates X chromosome to the gamete. In any case, the female always generates a similar kind of gamete. While the male either pass X or the Y chromosome to the progeny.

When the gamete with the X chromosome combines with the female gamete than the offspring would possess XX chromosomes and will be a female. On the other hand, when the gamete comprising the Y chromosome combines with the female gamete than the offspring would possess the XY chromosome and will be a male. Thus, it is the father who determines the gender of the offspring.

Answer 2

Wrong answers

• Girls get most of their traits from their moms; boys get most of their traits from their dads.

This is wrong. Parents gender does not affect traits passed on.

• Males never have Y chromosomes.

This is wrong, Males have to have a Y chromosome. (XY)

• Male offspring will always have an X-linked genetic disease if the mom is a carrier.

This is wrong. The male offspring have a 50/50 chance if the mother is a carrier, if she has the deseace than all the sons will have the decease.

Correct answer

• Fathers always determine the gender of the offspring in humans.

This is because the mom is XX and the dad is XY. The mom gives the X in the gene, and the dad gives the X for daughters (X,X) and gives the sons a Y (X,Y) Males are always XY.

If the mom is a carrier, h, then it will get passed down 50% of the time, and when it gets passed down to the males, they wiill have the deseace. If the mom passes the deacease down to the daughters, 50% will be a carrier too if the dad does not have the deseace. If the dad has the deacease, than 50% of the daughters will have the deacease, and the other 50% will be carrier, and still, 50% of the sons will have the deacease, while the other 50% will be completely clean. So in total 25% of the offspring will be a carrier, 50% will have the deacease, and the other 25% will not have the deacease or be a carrier.