Question

1. The XX Parent has genotype EE and the XY Parent has genotype EF. They have a triploid XY offspring that has genotype EEF.

This could have occurred through non-disjunction in meiosis II of the XY parent.
True or False

Answer 1

The statement is false because non-disjunction in meiosis II of the XY parent is not capable of producing triploid XY offspring with the EEF genotype.

What is meiosis II?

• It is the second stage of meiosis.
• This is where sister chromatids divide.

During meiosis II, nondisjunction is the result of the resistance of sister chromatids to the separation that occurs in meiosis II. When this happens, the chromatids remain united and this non-disjunction results in an offspring with an extra copy of the chromosome referring to these chromatids and does not result in a triplet of chromosomes, as shown in the statement in the question above.