L25 Cell cycle

Question 1

What three critical events does the cell cycle makes sure happens?

Answer 1

1. Chromosome replication
2. Chromosoem segregation
3. Cell division.

Question 2

How are normal cells stimulated to proliferate?

Answer 2

By extrinsic factors.

Question 3

How can a proliferation be forced to halt?

Answer 3

Overule of stimulatory factors by extracellular signals

Question 4

What is the structure of the cell cycle?

Answer 4

1. G1
2. S Phase.
3. G2
4. Mitosis Phase.

Question 5

What happens in G1 phase?

Answer 5

1. Cell increases in size
2. ribosomes and RNA produced
3. Preparation for DNA synthesis.

Question 6

What happens in S phase?

Answer 6

DNA is synthesised

Question 7

What happens in G2 phase?

Answer 7

1. Cell checks fidelity of DNA
2. Preparation for nuclear division.

Question 8

What are the sub phases of mitosis?

Answer 8

1. Prophase
2. prometaphase
3. metaphase
4. anaphase
5. Telophase.
6. Cytokinesis

Question 9

What is cell - free mitosis?

Answer 9

Technique that allows scientists to study the process of mitosis outside of a living cell

Question 10

How do we isolate the proteins that are responsible for cell cycle transitions?

Answer 10

Frogs eggs grow arrested in G2 to a relatively large size (good for extracting decent amounts of protein)

Oocytes arrested in G2, then under hormonal control mature and start meiosis BUT when they are laid they become stuck in meiotic metaphase ie M-phase. The are released by fertilization to start dividing (without growing)