Question
Question: What is the significance of meiosis? How does meiosis differ from mitosis?...
What is the significance of meiosis? How does meiosis differ from mitosis?
Solution
Mitosis is defined as a process wherein the sexually reproductive organism produces their sex cells, sperm and eggs.
Complete Answer:
Meiosis process is characterised by the presence of a specialised cell called the germ cell which undergoes a split to form four different sex cells. The significance of meiosis is,
- It is responsible for formation of sex cells which are responsible for sexual reproduction.
- It helps in maintaining constant chromosome number.
- It helps in activation of genetic information and deactivation of sporophytic information.
| Differentiating Factor | Mitosis | Meiosis |
|---|---|---|
| Interphase | Every single chromosome replicates and results into the production of two sister chromatids which are genetically identical to each other. | Chromosomes are not visible here as the DNA has either been replicated or duplicated. |
| Prophase | Each of the duplicated chromosomes portrays itself as two identical sister chromatids thereby progressing ahead with the formation of mitotic spindle fibres. The resulting chromosomes later condense and thicken. | This phase is characterised by crossing over recombination where two sister chromatids appear as pairs. The structure formed is known as the tetrad. |
| Metaphase | All the chromosomes assemble themselves at the equatorial axis | Chromosomes adjust themselves along the metaphase plate. |
| Anaphase | Spindle fibres features contraction and starts pulling sister chromatids apart. | Both the sister chromatids remain in intact contact with each other. |
| Mode of Reproduction | Asexual | Sexual |
| Occurrence | All cells | Reproductive cells |
| Function | General growth and reproduction | Genetic diversity via sexual reproduction |
| Cytokinesis | Telophase | Telophase I and II |
| Discovered by | Walter Fleming | Oscar Hertwig |
Note: The significance of mitosis is,
- It is required for asexual reproduction.
- It also helps in maintaining a constant number of chromosomes in body cells of all organisms.
- It helps in regeneration of damaged tissues.