Question

This is a cell molecular biology question from my class. Can someone please help me with this question? Please no diagrams or pictures from online copied and pasted here. I need a detailed explanation. Thank You!

Please draw the five levels of M phase in a diploid cell (2n) where n=2.

Answer 1

Mitotic phase of cell cycle includes both mitosis (karyokinesis) and cytokinesis. In animal cells karyokinesis (separation of nucleus) is usually followed by cytokinesis (separation of cytoplasm).

Mitosis is usually divided into four stages, prophase, metaphase, anaphase, and telophase. During mitosis, the division of nuclear material starts with the doubling of chromosomes, followed by distribution between two daughter nuclei in equal proportion.

Prophase is the first phase of cell division in both mitosis and meiosis. During this phase, cohesion that is present throughout the length of the chromatids is removed except at the centromere. The chromatids become more visible during this phase.

During the metaphase, two chromatids are formed from each chromosome by longitudinal splitting. These chromatids form the chromosomes of daughter cells.

During anaphase, centromeres are pulled and the chromatids become separated and move towards the opposite poles. These chromatids now are the chromosomes of the daughter cells, and are pulled towards the centrioles by means of spindle fibres.

In the stage of telophase, cytoplasmic division of the cell takes place (cytokinesis) during which each of the daughter cell receives one of the daughter nuclei. The interval between each division is called interphase. After cytokinesis, each chromosome duplicates (duplication of DNA, i.e., replication) forming two chromatids attached at centromere.

Mitosis, or somatic cell division centrioles aster centromere nucleus duplicated chromosome cytoplasm nucleolus nuclear membrane spindle fibre Parent cell, 2n Prophase 2n Late prophase, 2n Metaphase, 2n cell membrane Daughter cell, 2n Telophase and cytokinesis, 4n Anaphase, 2n