Question

How many meioses are required for the formation of 100 grains of wheat.
A.100
B.200
C.150
D.125

Answer 1

Hint:Meiosis is known as the reductional division which gives rise to four new daughter cells from one parent cell, and the number of chromosomes in each of the daughter cells reduces to half. In plants, the male both the male and female gamete mother cells undergo meiotic division.

Complete answer:The microspore mother cell in the anthers of plants, undergo meiotic division (meiosis I and II) and give rise to four haploid male gametes. All of these are functional and lead to fertilization. So, for four grains of wheat, one meiotic division is needed. Similarly, for producing 100 wheat grains, a net of 25 meiotic divisions would be needed.
Now, in plants, the male gamete, and female gamete fuse to form the zygote which ultimately develops into a seed. The female gamete mother cell undergoes meiosis to produce four haploid female gametes, out of which three degenerates and only one is functional. So, for the formation of 100 grains of wheat, a total of 100 female gametes are needed, which means a total of 100 meiotic divisions are needed.
Hence, including the number of meiotic divisions in both the male and female sex organs of the plant, a total of 125 divisions would give rise to 100 wheat grains.

So, the correct answer is option D. 125.

Note: It is important to note that meiosis occurs in plants only during the process of sexual reproduction in specialized cells to produce haploid gametic cells. Asexual reproduction is also found in plants but that takes place by mitotic divisions alone.