Biology XI Content
Differences between Mitosis and Meiosis
S.N.
| Meiosis
| |
1.
| It occurs in somatic cells and in germ cells during the multiplicative phase or gametogensis.
| It occurs in reproductive cells of gonads.
|
2.
| Mitosis completes in one sequence of stages i.e. in this cell division the cell divides once.
| The whole process completes into two successive divisions i.e. cell divides twice.
|
3.
| In mitosis, chromosome doubling is followed by separation of daughter chromosome i.e. there is division of centromere in mitosis.
| In meiosis, there is doubling of chromosomes once which is followed by two nuclear divisions, i.e. the centromere of chromosomes divides only once usually at the meiosis-II, or equational division phase.
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4.
| The daughter cells formed by this division are genetically similar to mother cell. Amount of DNA is same as in mother cell.
| The daughter cells formed by this division are genetically different from mother cell. Amount of DNA is half to that of mother cell.
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Prophase
| Prophase
| |
5.
| Prophase of mitosis is of short duration and is without sub stages.
| The prophase I of meiosis is of longer duration and completes in the five sub stages, viz., Leptotene, zygotene, pachytene, diplotene and diakinesis.
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6.
| The homologous chromosomes do not pair up with each other i.e. synapsis is absent.
| In meiosis I, the homologous chromosomes form pairs during the zygotene stage and it appears as if the chromosome number has become reduced to half.
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7.
| Duplication or splitting of chromosomes takes place in the early prophase.
| Duplication or splitting of chromosomes takes place in the late prophase (Pachytene stage).
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8.
| No chiasma formation or crossing over takes place.
| chiasma formation or crossing over takes place.
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9.
| The exchange of the genetic material between the homologous chromosomes does not occur.
| The exchange of the genetic material between the homologous chromosomes occurs.
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Metaphase
| Metaphase
| |
10.
| Chromosomes appear double stranded i.e. the chromatids occur in the form of dyads.
| Since, homologous chromosomes do not separate in prophase I, the chromosomes pairs appear in tetrad state, i.e. four stranded in metaphase-I.
|
11.
| The centromere of each chromosome divides into two and thus the two chromatids of the chromosome become free from each other.
| Centromere of the homologous chromosomes do not divide, thus their chromatids do not become free in the metaphase-I.
|
Anaphase
| Anaphase
| |
12.
| The two chromatids of each chromosome move towards the opposite poles of spindle.
| In meiosis I, the two homologous chromosomes of each pair separate and move towards the opposite poles of spindle during anaphase stage.
|
13.
| The daughter chromosomes appear in singlet state. | The separated chromosomes are two stranded but their centromere remains still in undivided state. However, the centromere is splitted into two in the metaphase II. |
14.
| The chromosomes are long and thin.
| The chromosomes are short and thick.
|
Telophase
| Telophase
| |
15.
| The telophase always occurs.
| The first telophase is sometimes absent.
|
16.
| Number of chromosome remains same as in mother cell.
| Chromosome number becomes half than the mother cell.
|
Cytokinesis
| Cytokinesis
| |
17.
| Cytokinesis always occurs.
| Cytokinesis-I may be absent.
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Significance
| Significance
| |
18.
| A diploid mother cell always produces two diploid cells by mitosis.
| A diploid cell produces four haploid cells by meiosis.
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19.
| Variations are not produced, so no role in evolution.
| Variations are produced due to crossing over, so plays important role in speciation and evolution.
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