Q.Differentiate between the events of mitosis and meiosis.

Mitosis and meiosis differ across almost every dimension — how many divisions occur, whether homologues pair up, and what the daughter cells end up looking like.

• Mitosis is a single division producing two daughter cells; meiosis is two successive divisions (following only one round of DNA replication) producing four daughter cells.
• Mitosis is an equational division, keeping the chromosome number the same in the daughter cells as in the parent; meiosis is a reduction division, halving the chromosome number so daughter cells are haploid where the parent was diploid.
• Mitosis never involves pairing of homologous chromosomes or crossing over; meiosis specifically involves synapsis of homologues into bivalents and crossing over between their non-sister chromatids during prophase I.
• Mitosis produces daughter cells genetically identical to the parent and to each other; meiosis, through crossing over and the independent separation of different chromosome pairs, produces genetically varied daughter cells. …

Comparing the two processes point by point brings out the contrast clearly:

• Number of divisions and resulting cells. Mitosis involves a single division, following one round of DNA replication, and produces two daughter cells. Meiosis involves two sequential divisions — meiosis I and meiosis II — following only a single round of DNA replication before both, and by the end produces four daughter cells (a tetrad).

• Chromosome number. Mitosis is described as an equational division: the chromosome number in the daughter cells is exactly the same as in the parent cell. Meiosis is a reduction division: it halves the chromosome number, producing haploid cells from a diploid parent.

• Pairing and recombination. Mitosis handles each chromosome individually; there is no pairing of homologous chromosomes and no crossing over. Meiosis, specifically during prophase I, involves synapsis — the pairing of homologous chromosomes into bivalents — followed by crossing over between the non-sister chromatids of the paired homologues, exchanging segments of genetic material.

• Genetic outcome. Mitosis produces daughter cells that are genetically identical to the parent cell and to each other. Meiosis, through crossing over and the independent way different chromosome pairs are distributed to the gametes, produces daughter cells that are genetically varied from one another and from the parent. …

Step 1 — Set up parallel comparison categories: number of divisions/cells produced, chromosome-number outcome, pairing/recombination behaviour, genetic outcome, and where each occurs.

Step 2 — Fill in mitosis's side: one division → 2 cells; equational (chromosome number unchanged); no homologue pairing/no crossing over; genetically identical daughters; mainly diploid somatic cells. …