Question

A family has a Y-linked disease that affects the father. What is the chance of a male offspring inheriting the same disease?

Answer 1

Answer: The correct answer is A) 100%.

Y linked disease is the one that is caused by genes present on the Y chromosomes. Females have XX and males have XY chromosomes that determine their gender. This means that Y chromosome is only present in males and all male offsprings inherit this chromosome from their father. Whereas, female offsprings inherit X chromosome ( from each parent).

As per the question, family has Y linked disease that affects father.

Thus, there will be 100% chances of inheriting this disease by the male offspring.

Answer 2

Remember that males have an x and y chromosome, while women have two x chromosomes. 

This means that a female offspring (daughter) inherits her father's only x chromosome and one of her mother's x chromosomes, while a male will receive his father's y chromosome and one of his mother's x chromosomes. 

This means that the boy will necessarily inherit his dad's Y chromosome, and any diseases that it carries. 

The chance of a male offspring inheriting the disease is 
A) 100%