Question

Which of the following occurs in meiosis II but not meiosis I?

Select one:

A. homologous chromosomes pair

B. homologous chromosomes cross-over

C. homologous chromatids separate

D. all of the above

E. none of the above

Answer 1

• Meiosis division is divided in two parts meiosis 1st and 2nd.
• By meiosis 1st a diploid mother cell is divided into two haploid daughter cells, which are different from each other and mother cell.
• By meiosis 2nd division, two haploid mother cells are divided into four haploid cells. This meiosis 2nd division is similar to mitosis division.

For meiosis 1st :-
• During prophase 1st, crossing over occurs between two homologous chromosomes.
• Two homologous chromosomes come together, bound tightly and form synapse. After that these chromosomes exchange their DNA, this process is called crossing over.
• In anaphase 1st, centromeres of chromosomes do not split and homologous chromosomes are separated and divided in both daughter cell. This results into half number of chromosomes (Haploid) in daughter cells.

Meiosis 2nd :-
• No homologous chromosome pairing, synapse and crossing over occur in this division.
• Centromeres of chromosomes split during anaphase 2nd and sister chromatids are divided in daughter cells. This results in same number of chromosomes in daughter cells.

Now in question,
Option (E) None of the above, is correct answer.
• All these statements are true for meiosis 1st and incorrect for meiosis 2nd.