Cell Cycle And Cell Division

DNA replication occurs in the phase, due to which the chromosome number doubles from to in the and phases. After mitosis, the cell returns to its state, hence the phase has chromosomes. Spermatogonia before replication are diploid and have chromosomes. They later divide to form haploid spermatocytes. Ova are haploid as they are gametes, and hence have chromosomes.

During late anaphase, the chromosomes are moving towards the poles of the cell. The centromeres are further from the equatorial plane compared to metaphase or early anaphase, as the chromatids are being pulled apart towards the poles.

During metaphase, chromosomes align at the metaphase plate, which is centrally located within the cell. This precise alignment is facilitated by the mitotic spindle, composed of microtubules. If a drug inhibits the formation of microtubules, it disrupts the formation of the spindle fibers necessary for aligning chromosomes correctly at the metaphase plate. Therefore, the inhibition of microtubule formation would first impact the metaphase stage of karyokinesis.

The incorrect statement is Option A.Explanation:Option A: “The end products of meiosis II are haploid gametes.”In plants, meiosis produces haploid spores (microspores in males, megaspores in females), not gametes.Gametes (sperm and egg) arise later by mitotic division within the haploid gametophyte.Option B: “The four products of meiosis are genetically different.”True, due to independent assortment and crossing-over.Option C: “Meiotic recombination takes place in both males and females.”True, recombination occurs during meiosis in both sexes.Option D: “In most flowering plants, only one of the four products of meiosis survives in females.”True, only one megaspore survives; the other three degenerate.