Cytoskeleton + Cell Cycle

Question 1

What does the cytoskeleton provide

Answer 1

Mechanical support and shape to cells

Question 2

What are microtubules composed of

Answer 2

Soluble globular proteins called tublin

Question 3

Where do microtubules radiate from

Answer 3

They radiate from the MTOC or centrosome

Question 4

What is the remodelling of the cytoskeleton required for

Answer 4

Cell division

Question 5

What results in the breakdown and formation of microtubules

Answer 5

Polymerisation and depolarisation of tublin

Question 6

When do microtubules activate

Answer 6

During cell division

Question 7

What does the cell cycle consist of

Answer 7

Interphase and mitotic phase (mitotic being cytokinesis and mitosis)

Question 8

What does mitosis consist of

Answer 8

• Prophase
• Metaphase
• Anaphase
• Telophase

Question 9

What is the interphase

Answer 9

Interphase consists of growth and DNA synthesis - includes:

• G1 - growth phase
• S phase - DNA is replicated
• G2 - further growth phase

Question 10

What does prophase consist of

Answer 10

• DNA condenses into chromosomes - forms two sister chromatids
• Spindle microtubules extent from MTOC by polymerisation and attaches by kinetochores in centromere region

Question 11

What occurs during metaphase

Answer 11

Chromosomes are aligned at metaphase plate (equator of spindle)

Question 12

What occurs during anaphase

Answer 12

• Depolymerisation shortens microtubules
• sister chromatids are separated
• chromosomes pulled to opposite poles

Question 13

What occurs at telophase

Answer 13

Chromosomes decondense and nuclear membranes form around them

Question 14

What occurs at cytokinesis

Answer 14

Cytokinesis occurs and forms two daughter cells

Question 15

What proteins accumulate during the cell cycle

Answer 15

Cyclin proteins accumulate and involved in regulating the cell cycle

Question 16

What does the metaphase checkpoint control

Answer 16

Controls progression of metaphase to anaphase and is halted unti chromosomes are aligned correctly on metaphase plate

Question 17

What occurs at the G1 checkpoint

Answer 17

Retinoblastoma protein acts as a tumour suppressor by inhibiting transcription of genes.

Question 18

What occurs at G2 checkpoint

Answer 18

Any damage to the DNA is assessed

Question 19

What does damage to the DNA trigger

Answer 19

Triggers activation of p53 which is protein that stimulates DNA repair, arrest of cell cycle, and cell death

Question 20

What occurs at the metaphase checkpoint

Answer 20

Metaphase to anaphase progression halted until chromosomes aligned correctly on metaphase plate

Question 21

What inhibits the retinoblastoma protein

Answer 21

Phosphorylation by G1 cyclin-CDK

Question 22

What could be a result of degenerative disease

Answer 22

Uncontrolled reduction in the rate of the cell cycle

Question 23

What could result in a tumour formation

Answer 23

An uncontrolled increase in the rate of the cell cycle

Question 24

What is the proto-oncogene

Answer 24

Gene involved in the control of cell growth or division which can mutate to form a tumour-promoting oncogene

Question 25

What are involve in regulating the cell cycle

Answer 25

Cyclin proteins that accumulate during cell growth