Question

Explain the stages of mitosis and meiosis, justifying the behaviour of chromosomes at each stage.

Please answer this question 350 words

Answer 1

The stages of mitosis:

Prophase: The chromatin condensation occurs the chromatin turns in to chromosomes.

Metaphase : All chromosome line up along the equator of the cell and  nuclear envelope dissoloves in this stage and it helps in the direct contact of microtubules with chromosomes.

Anaphase : During Anaphase the chromatid segragation occurs and the chromatids moves towards to poles.

Telophase : The chromosomes uncondences and forms chromatin. The nuclear membrane reforms.

The stages of meiosis: There is two stages in meiosis those are meiosis I and meiosis II

Meiosis I:

Prophase I: This prophase I includes five different stages.

Leptotene/leptonema - Lepto means thin and nema means thread. During this phase  chromatin condensation occurs the chromatin turns in to think chromosomes

Zygotene/Zygonema -  Zygo means mating and nema means thread. During this phase the holologous chormosome pairsup and formas tetrads.

Pachytene/Pachynema - Pachy menas thick and nema menas thread. During this phase the condensation occurs and forms thick chormosomes. During this phase the recombination occurs.

Diplotene - The chiasmata moves to wards the ends.

Diakinesis - nucleolus disappears, terminalization reaches to end, the chromosomes condenses and forms a thick and short chromosoems.

Metaphase I : All chromosome line up along the equator of the cell and  nuclear envelope dissoloves in this stage and it helps in the direct contact of microtubules with chromosomes.

Anaphase I: During Anaphase the chromosome segragation occurs and the chromosomes moves towards to poles. Here due to chromosome segregation, the chromosome number reduces to half.

Telophase I: The chromosomes uncondences and The nuclear membrane reforms.

Meiosis II

Prophase II: The chromatin condensation occurs the chromatin turns in to chromosomes.

Metaphase II : All chromosome line up along the equator of the cell .

Anaphase II: During Anaphase the chromatid segragation occurs and the chromatids moves towards to poles.

Telophase II: The chromosomes uncondences and forms chromatin. The nuclear membrane reforms.