Question

nondisjunction during meiosis results in an abnormal number of chromosomes in one or more gametes. in some cases of nondisjunction, a single chromosome fails to separate. in others, none of the chromosomes separate. suppose an egg is produced in which none of the chromosomes separate during meiosis ii. what is the chromosome number of the zygote that results if this egg is fertilized by a normal sperm?
1n
2n
2n + 1
3n

Explanation:

Normal sperm has a haploid (n) number of chromosomes. When meiosis - II non - disjunction occurs in egg - formation and none of the chromosomes separate, the egg has a diploid (2n) number of chromosomes. When a diploid egg (2n) is fertilized by a normal haploid sperm (n), the resulting zygote has 3n chromosomes.

Answer:

D. 3n