mitosis. Interphase is made up of phases: G1, S phase, and G2. The G1 and G2 phases are checkpoints for the cell

The Cell Cycle

The cell cycle is a process that is subject to control at multiple points along the pathway. These control points include both the G1/S and G2/M transitions of interphase as well as anaphase of mitosis. These checkpoints are critical in ensuring genome is preserved.

Interphase is made up of phases: G1, S phase, and G2. The G1 and G2 phases are checkpoints for the cell to make sure that it is ready to proceed in the cell cycle.. S phase involves the replication of chromosomes. All three stages of interphase involve continued cell growth and an increase in the concentration of proteins found in the cell.

G1, S, and G2 are collectively called interphase.

G1 stands for gap 1, or presynthesis; S for synthesis; G2 for gap 2, or postsynthesis.

M is the mitotic division phase.
chromosomes are replicated during the S (synthesis) phase of the cell cycle before mitosis can begin.

Mitosis: -- Mitosis is the process where one set of chromosomes is equally dividing into two identical groups. The new "daughter" cell has exactly the same number of chromosomes and information as the "parent" cell. 1 cell divides and becomes 2 cells.

Prophase: The chromatin, diffuse in interphase, condenses into chromosomes. Each chromosome consists of 2 chromatids . Cohesin holds chromatids together The cell's centioles are duplicated to form two pairs of centrioles. Each pair becomes the part of the mitotic center which forms the microtubules, called the aster. The two asters lie side by side close the the nuclear envelope. Near the end of prophase the asters pull apart and the spindle is formed. Nuclear envelope disappears.

PROMETAPHASE

When the microtubules attach to chromosomes, they attach to a specialized structure called the kinetochore is ...

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PROMETAPHASE

When the microtubules attach to chromosomes, they attach to a specialized structure called the kinetochore is fromed on the centromeres called microtubules. The microtubules enter the nuclear region. Centrosomes complete migration to opposite poles

Metaphase:

The chromosomes align at the equitorial plate and are held in place by microtubules attached to the mitotic spindle and to part of the centromere. Then the Chromosomes are lined up single file in the center of the cell. spindle fibers extend from one side of the cell to the other.

Anaphase: the duplicated centromeres of each pair of sister chromatids separate, and the now-daughter chromosomes begin moving toward opposite poles of the cell due to the action of the spindle. Movement is generated by motor proteins using ATP. Motor protein 1 is in the kinetochore, as the chromosome moves tubulin units are lost. Motor protein 2– occur at the free ends of the polar microtubules, these cause the poles to move apart by adding tubulin molecules at the positive end .At the end of anaphase, a complete set of chromosomes has assembled at each pole of the cell.

Telophase: the Daughter chromosomes arrive at the poles and the microtubules disappear. The condensed chromatin expands and the nuclear envelope reappears. Chromosomes then unwind and Spindle fibers disappear .Chromosomes, now at opposite sides of the cell, are surrounded by new nuclear envelope.

Cytokinesis begins.. The fibre ring composed of a protein called actin around the center of the cell contracts pinching the cell into two daughter cells, each with one nucleus.

Differences between Mitosis and Meiosis