Q.Give a comprehensive comparative account of mitosis and meiosis, covering where each occurs, the number of divisions involved, whether homologous chromosomes pair and undergo crossing over, and the chromosome number and genetic composition of the daughter cells each process produces.
You're viewing a preview — the full solution, concept, methods & PYQ mapping are locked.
Start your 14-day free trial to unlock the full solution →Mitosis and meiosis are both forms of nuclear division built on the same basic machinery of condensed chromosomes and a spindle apparatus, yet they differ across every major point of comparison.
Occurrence: mitosis takes place in the somatic (body) cells of an organism, while meiosis is restricted to the specialised germ cells that give rise to gametes.
Number of divisions: mitosis involves a single division of the parent cell. Meiosis involves two successive divisions, meiosis I and meiosis II, occurring without an intervening round of DNA replication between them.
Pairing of homologous chromosomes: in mitosis, the two members of a homologous pair behave entirely independently of one another throughout the division and never pair up. In meiosis, homologous chromosomes actively pair with one another during zygotene of prophase I, a process called synapsis that forms structures called bivalents, stabilised by the synaptonemal complex.
Crossing over: mitosis involves no exchange of genetic material between chromosomes at all. Meiosis involves crossing over during pachytene of prophase I, when non-sister chromatids of a bivalent reciprocally exchange segments of genetic material at recombination nodules, an event with no counterpart anywhere in mitosis. …
Unlock everything free for 14 days
- Full step-by-step solutions
- Concept-first explanations
- Methods, shortcuts & mistakes
- PYQ mapping + timed mock tests
Full access for 14 days. No credit card required.