|It occurs in all somatic cells and may
persist all over life
|It occurs in reproductive cells at
|It involves a single division, which
leads to two daughter cells only.
|It involves two successive divisions,
which leads to four daughter cells.
|Consequent mitotic divisions are
similar to the previous ones.
|Two meiotic divisions are dissimilar,
the first is reductional while
the second is equational.
|Prophase is relatively short and simple.||Prophase I is very long and elaborate, which comprises
five subphases like leptotene, pachytene,
zygotene, diplotene, and diakinesis.
|There is no pairing of homologous chromosomes.||Homologous chromosomes pair and often
undergo crossing over in prophase I.
|Chromatids are genetically similar to
the chromosomes they arise from
|Chromatids may vary genetically from the chromosomes
they emerge from because of crossing over.
|No synaptonemal complex formed.||Synaptonemal complex forms among
synapsed homologous chromosomes.
|Chromosomes do not unfold, and no protein
synthesis and transcription take place in prophase.
|Chromosomes unfold, n and protein synthesis
and transcription may take place in diplotene
of prophase I (oocytes of specific animals).
|Daughter cells have a diploid number (2N)
of chromosomes like the parent cell.
|Daughter cells have a haploid number
(N) of chromosomes, unlike the parent cell.
Analyse the events during every stage of cell cycle and notice how the following two parameters change
(i) number of chromosomes (N) per cell
(ii) amount of DNA content (C) per cell
Can there be mitosis without DNA replication in the ‘S’ phase?
Discuss with your teacher about
(i) haploid insects and lower plants where cell-division occurs.
(ii) some haploid cells in higher plants where cell-division does not occur.
What is the significance of meiosis?
Distinguish anaphase of mitosis from anaphase 1 of meiosis.