For formation of 4 pollen grains = 1 Meiotic division is required, so for the formation of 105 pollen grains = 1/4 × 105 = 26.25 meiotic division are required. This is according to calculation but we have to use common sense that half a pollen can't be formed, so 27 meotic divisions will take place...

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Explanation:

Meiosis is the process of cell division that halves the number of chromosomes in a cell. It is the process by which gametes (sex cells) are formed. The diploid cell undergoes two rounds of cell division resulting in four haploid cells.

- Meiosis I: Homologous chromosomes separate, resulting in two haploid cells with duplicated chromosomes.
- Meiosis II: Sister chromatids separate, resulting in four haploid cells with unduplicated chromosomes.

Each round of meiosis involves one cell division, so the number of meiotic divisions required to produce 105 pollen grains can be calculated as follows:

- Each pollen grain is haploid, meaning it has half the number of chromosomes as the parent cell, which is diploid.
- If we assume that the parent cell has 2n chromosomes, then each haploid pollen grain will have n chromosomes.
- Therefore, to produce 105 haploid pollen grains, we need 210 chromosomes in total.
- If each meiotic division halves the number of chromosomes, then we need two rounds of meiosis to produce 105 pollen grains.
- Therefore, the answer is 27, as two rounds of meiosis involve two cell divisions.

Conclusion:

To produce 105 pollen grains, two rounds of meiosis are required, which involves two cell divisions. Therefore, the correct answer is (B) 27.