Cell Cycle

Question 1

The cell cycle

G1-S-G2-M

Answer 1

The cell cycle regulates the growth and replacement of genetically identical cells throughout the lift of the organism

Question 2

The cell cycle consists of interphase and mitotic (M) phase

Answer 2

Interphase - Involves growth and DNA synthesis including G1, a growth phase; S phase, during which DNA is replicated; G2, a further growth phase

Mitotic (M) phas - Mitotic phase involves mitosis and cytokineses

In mitosis the chromosomal material is seperated by the spindle microtubules. The is followed by cytokineses, in which the cytoplasm is separated into two daughter cells.

Question 3

Mitosis

prophase, metaphase, anaphase, telophase

Answer 3

Prophase - DNA condenses into chromosomes each consisting of two sister chromatids. Nuclear membrane breaks down; spindle microtubules extend from the MTOC by polymerisation and attach to chromosomes via their kinectochores in the centromere region.

Metaphase - Chromosomes are aligned at the metaphase plate

Anaphase - As spindle microtubules shorten by depolymerisation, sister chromatids are seperated, and the chromosomes are pulled to opposite poles.

Telophase - The chromosomes decondense and nuclear membrane are formed around them.