Question

Non-disjunction may occur due to the failure of ......chromosomes to separate properly in meiosis I.

A. homologous

B. non-homologous

C. autosomal

D. All of the above

Answer 1

Nondisjunction may occur due to the failure of homologous chromosomes to separate properly in meiosis I. This can result in gametes with abnormal chromosome numbers.

Step-by-step explanation:

d. All of the above

Nondisjunction may occur due to the failure of homologous chromosomes to separate properly in meiosis I. This means that the chromosomes that should have separated and gone to different daughter cells remain together in one cell, leading to the formation of gametes with abnormal chromosome numbers.

For example, if homologous chromosomes fail to separate during meiosis I, the result is two gametes that lack that chromosome and two gametes with two copies of the chromosome. If sister chromatids fail to separate during meiosis II, the result is one gamete that lacks that chromosome, two normal gametes with one copy of the chromosome, and one gamete with two copies of the chromosome.