The Cell Cycle And Its Control

Question 1

What are some reasons affecting proliferation?

Answer 1

j

Question 2

What is the result of premature, aberrant mitosis?

Answer 2

Cell death

Question 3

What are the nucleus of tumours like/

Answer 3

Aneuploid - abnormal chromosome number and content

Question 4

What is the cell cycle?

Answer 4

Orderly sequence of events in which a cell duplicates its contents
and divides in two.

Question 5

What is the regulated progression through the cell cycle

Answer 5

M-phase: mitosis
- nuclear division
- cell division (cytokinesis)
Interphase: duplication 
-DNA
-organelles
-protein synthesis

Question 6

What is the most vulnerable period of the cell cycle and why>

Answer 6

Mitosis - most vulnerable period of cell cycle:

• Cells are more easily killed (irradiation, heat shock, chemicals)
• DNA damage can not be repaired
• Gene transcription silenced
• Metabolism?

Question 7

What is the order of the eukaryotic cell cycle

Answer 7

M phase - mitosis
Interphase:
 - G0 - cell cycle machinery dismantled
 - G1 - decision point 
 - S - synthesis of DNA/protein
 - G2 phase - decision point

Question 8

What happens during the S phase?

Answer 8

Replication for division

DNA replication

Protein synthesis: initiation of translation and elongation increased; capacity is also increased

Replication of organelles (centrosomes, mitochondria, Golgi, etc)
in case of mitochondria, needs to coordinate with replication of mitochondrial DNA

Question 9

What is the centrosome

Answer 9

Consists of two centrioles (barrels of nine triplet microtubules)

Question 10

What are the functions of the centrosome

Answer 10

Microtubule organising center

Mitotic spindle

Question 11

What are the phases of mitosis?

Answer 11

Prophase
Prometaphase
Metaphase
Anaphase
Telophase
Cytokinesis

Question 12

What happens in prophase?

Answer 12

.