Topic 2 - Cell functions

Question 1

What is the 4 main phases of mitosis?

Answer 1

• G1 (check for DNA damage, enough nutrients and verify cell size)
• S-phase (DNA replication occurs)
• G2 (Check DNA replicated correctly)
• M (mitotic phase - PMAT)

Question 2

What is the G0 phase?

Answer 2

performs unique functions without cell growth or division

Question 3

What is a protein that regulates cell cycle?

Answer 3

Cyclin = activates cyclin-dependent kinase (CDK)
There are different Cyclin proteins for initiation of a certain phase & concentration indicates next stages

Question 4

What are the cells that can be used for differentiation?

Answer 4

Stem cells = reproduce indefinitely & are undifferentiated meaning they can become any cell - pluripotent

Question 5

What is Apoptosis?

Answer 5

It is regulated cell death

*Cancer occurs when apoptosis process is inhibited

Question 6

What are the general steps of apoptosis?

Answer 6

1. Chromosomes condense
2. DNA fragments
3. Cytoplasm condenses
4. Cell breaks up into membrane-bound fragments
5. fragments engulfed by phagocytes like macrophages

Question 7

What is the difference between necrosis and apoptosis?

Answer 7

Apoptosis = regulated cell death (doesn’t cause inflammation as macrophages engulf remains)
Necrosis = cell death induced by injury - can result in inflammation

Question 8

What is a transit cell in haematopoiesis?

Answer 8

Common myeloid progenitor