The Importance Of The Cell Cycle

1.1 Cell cycle

Growth and reproduction of eukaryotes depend on the cellular life cycle (cell cycle) whereby the cell duplicates its components to physically split into two identical daughter cells. In general, the cell cycle is divided into two phases: interphase where cell growth and DNA replication takes place, and mitosis where the duplicated DNA is divided into two daughter cells.The interphase of the cell cycle is further sub-divided into three discrete phases: G1, S and G2. During interphase, the cell is metabolically active and has distinct biochemical processes that prepares the cells for the cell division.

G1 phase ( or gap 1 phase) of the cell cycle corresponds to the gap between mitosis and initiation of DNA replication in the subsequent

The nucleous disappear and the mitotic spindle begin to appear as the two duplicated centrosome move to the opposite poles.

Prometaphase

Prophase is followed by the breaking down of nuclear envelope into many small vesicles that will eventually be divided between daughter cells. This process is essential for the microtubules from mitotic spindle to access and capture chromosomes. During this phase, microtubules are extremely dynamic that is they assemble and disassemble as they grow out to capture chromosomes. As this phase ensues, the captured chromosomes are then pulled and tugged in opposite directions until kinetochores on each sister chromatids are connected by microtubules to opposite poles of the spindle.

Metaphase

The Metaphase is characterised by aligning the captured chromosome to form a metaphase plate along the middle of the cell and this organisation ensures proper chromosome segregation in the next phase.

Anaphase

This phase of the cell cycle begins with the separation of sister chromatids through degradation of the cohesin molecules by separase. It is then followed by shortening of kinetochore micro-