Question

Diploid chromosome number is 8. What shall be the number of chromatids in each daughter cell after meiosis I?
A. 10
B. 8
C. 4
D. 2

Answer 1

Hint: Meiosis occurs in eukaryotes to produce haploid sex cells. It is also known as chromosomal reduction division where a diploid cell is reduced to form two haploid cells (these cells have only one chromosome set). The sex cells or gametes are essential for sexual reproduction. The male and the female gametes fuse to form a diploid zygote. In a diploid cell, the chromosome number is given by the formula 2n.

Complete answer:
Option A -10 -At the end of meiosis I, two haploid daughter cells are formed. It is given that the diploid chromosome number is 8. By the formula 2n=8, then n must be 4. Hence, the chromosome number in each haploid cell is 4 and the chromatid number is 8. This option is wrong.
Option A is incorrect.
Option B – 8 - Since the number of chromatids in each daughter cell is 8, this option is correct.
Option B is correct.
Option C – 4 - After meiosis I, only the chromosome number is 4. Each chromosome contains two chromatids and so the chromatids number will be 8. This option is wrong.
Option C is incorrect.
Option D - 2 - The number of chromatids in each cell is 8 and not 2.
Option D is incorrect.

Hence, Option: B -8 is the correct answer.

Note:
 Meiosis occurs in two stages- meiosis I and meiosis II. In meiosis I, the homologous chromosomes pair together as tetrads. These divide to give 2 haploid daughter cells with half the number of chromosomes.During meiosis II, the sister chromatids of chromosomes in each cell separate which once again doubles the chromosome number (i.e.2n). The cells further divide to form four new haploid daughter cells (n).