In sexually reproducing organisms, before fertilisation, gametes are formed by reduction division toI. increase the genetic variation.II. reduce the chances of mutation.III. ensure the diploid number of chromosomes in zygote.
Correct answer: B. III only
- A. I only
- B. III only
- C. I and II
- D. II and III
Explanation
Reduction division, or meiosis, occurs in sexually reproducing organisms to produce gametes with half the chromosome number. This ensures that when fertilization occurs, the resulting zygote has the correct diploid chromosome number (III). While meiosis introduces genetic variation, its primary function is not to increase genetic variation, which makes option B (III only) the correct answer. The chances of mutation are not reduced in meiosis.
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About Chromosomes
Chromosomes are DNA-protein structures that carry genes and become visible during cell division. Coverage includes chromatin, centromeres, sister chromatids, homologous chromosomes, chromosome number, and the distinction between diploid and haploid cells, with links to DNA replication, mitosis and meiosis.
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