Question

Why is meiosis important for organisms?

Answer 1

Like mitosis, meiosisis a form  of eukaryotic cell division. However, these two processes distribute genetic material among the resulting daughter cells in very different ways. Mitosis creates two identical daughter cells that each contain the same number of chromosomes as their parent cell. In contrast, meiosis gives rise to four unique daughter cells, each of which has half the number of chromosomes as the parent cell. Because meiosis creates cells that are destined to become gametes(or reproductive cells), this reduction in chromosome number is critical — without it, the union of two gametes during fertilization would result in offspring with twice the normal number of chromosomes!

Apart from this reduction in chromosome number, meiosis differs from mitosis in yet another way. Specifically, meiosis creates new combinations of genetic material in each of the four daughter cells. These new combinations result from the exchange of DNA between paired chromosomes. Such exchange means that the gametes produced through meiosis exhibit an amazing range of genetic variation.

Finally, unlike mitosis, meiosis involves two rounds of nuclear division, not just one. Despite this fact, many of the other events of meiosis are similar to those that occur in mitosis. For example, prior to undergoing meiosis, a cell goes through an interphase period in which it grows, replicates its chromosomes, and checks all of its systems to ensure that it is ready to divide. Like mitosis, meiosis also has distinct stages called prophase, metaphase, anaphase, and telophase. A key difference, however, is that during meiosis, each of these phases occurs twice — once during the first round of division, called meiosis I, and again during the second round of division, called meiosis II.

Answer 2

Meiosis is important for organisms because:

• Meiosis is the process of cell division in living organisms for producing gamete cells which are eggs (in females) and sperms (in males).
• Through this cell division process, a single cell divides two times and chromosomes are reduced to half the number in both the parent cells.

1. Formation of zygote cell: When fertilization occurs male and female gamete with half number of chromosomes is fused and chromosome number is restored to the original number in the zygote. It contains chromosomes and hence traits from both parents.
2. Variation and Evolution: During the stages of meiosis the segments in chromatids are crossed, making chromosomes that contain varied gene sequences. This gene sequence leads to variation and develops certain characteristics in children which helps to cope with unfavourable conditions.

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