Question

3. Discuss the cell cycle: Name the phases of the cell cycle. Describe the relative time spent in each of these stages. What main events happen in each stage?

Answer 1

Cell cycle is a series of events which occurs in the cell which results in the division/duplication of its DNA in order to produce two daughter cells. The following are the stages of cell cycle - interphase (G₁, S and G₂ phases), mitotic phase (mitosis and cytokinesis) and G₀ phase.

Time spent in each phase is -

G₁ -10 hours

S - 5-6 hours

G₂ - 3-4 hours

Mitotic phase - 2 hours

Main events that occurs in G₁ is the metabolic changes which helps the cell in division. S phase is the synthesis phase where the genetic material replicates. In G₂ phase metabolic changes assembles the cytoplasmic material which are required for mitosis and cytokinesis. In mitotic phasphase, mitosis (nuclear division) followed by cytokinesis (cell ddivision) occurs.