1.5 Protein Control of Cell Division

Question 1

What does the cell cycle consist of?

Answer 1

Interphase and Mitotic Phase

Question 2

What does the mitotic phase consist of?

Answer 2

Mitosis and Cytokinesis

Question 3

What does mitosis consist of?

Answer 3

Prophase, Metaphase, Anaphase and Telophase

Question 4

Cytoskeleton

Answer 4

Gives mechanical support and shape to cells

Question 5

Microtubules

Answer 5

Control the movement of membrane-bound organelles and chromosomes

Question 6

Microtubule Formation

Answer 6

Polymerisation of Tubulin

Question 7

Microtubule Breakdown

Answer 7

Depolymerisation of Tubulin

Question 8

Stages of Interphase

Answer 8

G1, a growth phase; S phase, during which the DNA replicates; and G2, a further growth phase in preparation for mitosis.

Question 9

G1 Checkpoint

Answer 9

Retinoblastoma protein (Rb) acts as a tumour suppressor by inhibiting the transcription of genes that code for proteins needed for DNA replication. Phosphorylation by G1 cyclin-CDK inhibits the Rb

Question 10

G2 Checkpoint

Answer 10

Success of DNA replication and any damage to DNA is assessed

Question 11

DNA Damage Process

Answer 11

DNA damage triggers activation of p53 that can stimulate DNA repair, arrest the cell cycle or cause cell death

Question 12

Metaphase Checkpoint

Answer 12

Controls progression from metaphase to anaphase

Question 13

Degenerative Disease

Answer 13

Uncontrolled reduction in rate of cell cycle

Question 14

Tumour Formation

Answer 14

Uncontrolled increase in rate of cell cycle

Question 15

Proto-Oncogene

Answer 15

Normal gene, usually involved in the control of cell growth or division, which can mutate to form a tumour-promoting oncogene

Question 16

How is apoptosis triggered?

Answer 16

Internal or External Death Signals

Question 17

External Death Signalling

Answer 17

Signal molecules bind to a surface receptor protein and trigger a protein cascade within the cytoplasm

Question 18

Internal Death Signalling

Answer 18

Results from DNA damage causing activation of p53 tumour-suppressor protein

Question 19

What do both types of death signals activate?

Answer 19

Caspases (types of protease enzyme) which break down proteins

Question 20

Apoptosis

Answer 20

Programmed cell death, which can occur during normal growth and development, resulting in the removal of old or damaged cells or during metamorphosis in certain species.