Question

1)

Which of the following processes might produce a human zygote with 45 chromosomes?

A)a non-disjunction in meiotic anaphase occurring in either an egg or sperm

B)failure of the egg nucleus to be fertilized by the sperm

C)failure of an egg to complete meiosis II

D)incomplete cytokinesis during spermatogenesis after meiosis I

2)Which of the following characteristics of eukaryotic chromosomes cause them to shorten every time the DNA is replicated?

A)DNA polymerase that cannot replicate the leading strand template to its 5' end

B)gaps left at the 5' end of the lagging strand template

C)the activity of telomerase enzyme

D)gaps left at the 3' end of the lagging strand because of the need for a primer

Answer 1

Question 1:

Answer : A)a non-disjunction in meiotic anaphase occurring in either an egg or sperm

Explanation : the above process like error in egg and sperm can cause to chromosomes number 45 in the human being .the normal chromosome number is 45 but when non-disjunction occour in during the cell division in meiotic phase then cause for genetic disorder by abnormal number of chromosome.

Question 2:

Answer : C) the activity of telomerase enzyme.

Explanation :the telemerase activity is most important during the replication it help to attach with the chromosomes .as the activity or absence of telemerase enzyme then cause chromosomes shortened after each and every round of process replication.