Unit 1: Control of the Cell Cycle

Question 1

The control of the cell cycle can be studied using model organisms such as?

Answer 1

Yeast

Question 2

When does the G1 checkpoint take place?

Answer 2

At the end of G1 before S phase

Question 3

When does the G2 checkpoint take place?

Answer 3

At the end of G2 before the start of the M-phase

Question 4

When does the M checkpoint take place?

Answer 4

Before the beginning of anaphase

Question 5

What is checked for at the G1 checkpoint?

Answer 5

Cell size and environmental conditions

Question 6

What is checked for at the G2 checkpoint?

Answer 6

Correct replication of DNA

Question 7

What is checked for at the M checkpoint?

Answer 7

Chromosomes correct attachment to spindle fibres

Question 8

Cells need an adequate nutrient supply to proliferate, plus what else?

Answer 8

Serum

Question 9

Serum needed for cell proliferation contains a protein causes what to happen?

Answer 9

It stimulates the cells to continue through the cell cycle

Question 10

Extracellular signal molecules with the ability to stimulate the cell to continue the cell cycle are called?

Answer 10

Mitogens

Question 11

Mitogens are?

Answer 11

Extracellular signal molecules with the ability to stimulate the cell to continue the cell cycle

Question 12

In the absence of Mitogens what happens to the cell cycle?

Answer 12

Cells in the cycle enter the G0 phase

Question 13

What happens in the G0 phase of the cell cycle?

Answer 13

Cells don’t divide

Question 14

For how long do the cells remain in the G0 phase of the cell cycle?

Answer 14

They can remain here forever or re-enter the cell cycle when appropriate.

Question 15

Give two examples of cells than can proliferate continuously

Answer 15

Stem cells and Tumour cells

Question 16

Liver cells exist constantly in the G0 phase until?

Answer 16

The liver becomes damages and new cells are needed

Question 17

Give the three type of cells that exist in terminally differentiated states?

Answer 17

Red blood cells, Neurons and Skeletal Muscle

Question 18

The cell cycle is controlled by the activity of what?

Answer 18

Cyclin dependent kinases (Cdk)

Question 19

The cell cycle control system can be studied using model organisms such as

Answer 19

Spisula

Question 20

High release levels of cyclin proteins indicate what process is taking place?

Answer 20

Mitosis

Question 21

The activity of Cdks is regulated by

Answer 21

cyclins

Question 22

Different cyclins bind to Cdks when?

Answer 22

At different phases of the cell cycle

Question 23

A cyclin binds to G1 Cdk to allow…

Answer 23

cell passage through G1 checkpoint

Question 24

A cyclin binds to S Cdk to allow…

Answer 24

a cell to initiate DNA replication

Question 25

A cyclin binds to M Cdk to promote...

Answer 25

Mitosis

Question 26

A certain level of phosphorylation of what cells, results in the cell progressing to the next stage of the cycle?

Answer 26

Target proteins

Question 27

Active Retinoblastoma protein (Rb) does what?

Answer 27

Inhibits cell cycle progression

Question 28

Retinoblastoma is target by what?

Answer 28

G1-Cdk

Question 29

Once the G1-Cdk works on the retinoblastoma two what are added causing the retinoblastoma to go from active to active?

Answer 29

Phosphates

Question 30

P53: Stage 1, Mutagen damages DNA triggering what?

Answer 30

Protein kinase activity

Question 31

P53: Stage 2, Protein kinase activity causes what to happen to p53?

Answer 31

It goes form unstable to stable by addition of a phosphate

Question 32

P53: Stage 3, Activated P53 induced what?

Answer 32

Transcription of genes that cause cell cycle arrest

Question 33

P53: Stage 4, Cell cycle arrest gene ______ is expressed?

Answer 33

p21

Question 34

P53: Stage 5, Production of p21 causes the cyclin-cdk complex to become?

Answer 34

inactivated

Question 35

What are the top three things Activated p53 does?

Answer 35

Stimulates DNA repair, promotes transcription of cell cycle arresting genes and genes that induce apoptosis

Question 36

What is the name of a genetic disease associated with the inability to activate p53?

Answer 36

Ataxia telangiectasia