Question

"Mitosis and Meiosis I are very different, but Mitosis and Meiosis II are very similar. Therefore, Meiosis I must cause all the key differences between gametes and normal body cells." Do you agree or disagree with this statement?

Answer 1

Answer:

Agree

Explanation:

1. Through mitosis, Parental cell divide into two daughter cells with same number of chromosomes.

While meiosis produce 4 daughter cell from a single cell  with half the number of chromosomes as compared to parental cell.

2.Meiosis have two cycles , i) meiosis I and ii) meiosis II.

3. In meiosis I, chromosomes first go replication and become double, then cell  inter into meiosis I then into meiosis II and finally  produce four haploid daughter cells. It is the first step (meiosis I) that generates genetic diversity. During prophase I of meiosis I (meiosis)  homologous chromosomes pair and form synapses, a special step of meiosis, which is the main reason of causing diversity.

4. There is crossing over which produce genetic diversity between gametes.

Answer 2

Mitosis and Meiosis I

Explanation:

Mitosis

• Mitosis is one round replication and one round division, here genetic recombination is absent hence daughter cells are identical to parental cell
• It includes two divisions: karyokinesis and cytokinesis
• Karyokinesis includes separation of sister chromatids from a replicated chromosome and includes four sequential sub-phases: prophase,metaphase,anaphase,telophase
• Prophase includes three major events: compaction of chromosome,assembly of mitotic spindle apparatus and disappearance of nuclear envelope
• Metaphase occurs when all chromosomes are arranged at metaphase plate
• Anaphase includes two major events: separation of two sister chromatids and movement of sister chromatids towards their respective poles
• Telophase includes aggregation of two sets of chromosomes near the respective poles
• Telophase is followed by cytokinesis where cytoplasm is divided into two which results in the generation of two daughter cells

Meiosis I

• Meiosis I is the long phase where number of chromosomes is reduced and just becomes half
• Separation of homologous chromosomes occur
• Genetic recombination also occurs in meiosis I
• Also completed in four sequential phases: prophase I, metaphase I, anaphase I, telophase I

Meiosis II

• Meiosis II is similar to mitosis
• Also includes 4 phases: prophase II,metaphase II, anaphase II, telophase II
• Separation of sister chromatids occur in Anaphase II

Meiosis II is similar to mitosis because it separates the chromosomes to have sister chromatids in each cell

In both these process, chromosome are separated and cell divides to make two cells out of one

The key difference is that in meiosis,two cells are divided to get four cells

Meiosis I helps to get genetically unique chromosomes,crossing over occurs and at the end of division one parent cell produces two daughter cells each carrying one set of sister chromatids whereas mitosis is used to make body cells occurring in body