regulation of cell cycle and cancer

Question 1

What is the nondisjunction in 1st division?

Answer 1

First-division nondisjunction

Question 2

What is the nondisjunction in the 2nd division?

Answer 2

Second-division nondisjunction

Question 3

What is the result of 1st division nondisjunction?

Answer 3

2 gametes with extra chromosome, 2 gametes misising chromosome

Question 4

What is the result of 2nd division nondisjunction?

Answer 4

two normal gametes, one gamete with extra chromosome, a gamete with missing chromosome

Question 5

What are resulted from non-disjunction in the maternal meiotic cell division?

Answer 5

triisomies

Question 6

What do oscillating cyclin levels suggest?

Answer 6

They are important for progression through the cell cycle

Question 7

How many cyclin proteins are there?

Answer 7

Multiple that rise and fall throughout the cell cycle

Question 8

What does each cycle react to specifically?

Answer 8

a cyclin-dependent kinase(CDK)

Question 9

What does the cyclin and CDK do when they come together to a target protein?

Answer 9

Phosphorylates it(adds phosphate)

Question 10

By phosphorylating proteins, what happens next?

Answer 10

the next phase starts–replication enzymes are initiated

Question 11

What kind of experiment would demonstrate that a CDK is required for progression?

Answer 11

Removing it

Question 12

What type of experiment would demonstrate that a CDK is sufficient for progression?

Answer 12

Removing it

Question 13

What type of experiments have contributed greatly to our understanding of cyclin/cdk signaling

Answer 13

fission yeast

Question 14

What would lead to uncontrolled cell division?

Answer 14

a mutant cdk that is active even in the absence of its cyclin partner

Question 15

What are the three things to make sure in the G1/S checkpoint?

Answer 15

1.Cell commit to DNA replication
2. DNA damage to repair
3. sufficient energy and nutrients

Question 16

What are the two things to make sure in the G2/M checkpoint

Answer 16

1. DNA replication successful
2. cell volume large enough to divide

Question 17

What are the two things to make sure in the metaphase/ M checkpoint?

Answer 17

1. all chromosomes are attached to spindle
2. all chromosomes are properly aligned at metaphase plate

Question 18

What does p53 do in the cell cycle

Answer 18

inhibits progression to S phase if DNA damage is detected

Question 19

How is p53 turned on to inhibit?

Answer 19

it is phosphorylated

Question 20

What is a mutagen

Answer 20

something that induces DNA mutations or damage

Question 21

Physical mutagen

Answer 21

UV light

Question 22

Chemical mutagen

Answer 22

EMS

Question 23

Biological mutagen

Answer 23

virus

Question 24

Proto-oncogene

Answer 24

normal gene important in cell division that has potential to cause cancer if mutated

Question 25

oncogene

Answer 25

mutated, cancer-causing gene

Question 26

tumor supressors

Answer 26

proteins whose normal activities inhibit cell division

Question 27

If cells are exposed to the chemical mutagen EMS immediately after mitosis, at which checkpoint would the cell probably arrest?

Answer 27

G1/S

Question 28

What do proto-oncogenes code for?

Answer 28

proteins that promote the cell cycle

Question 29

What does a proto-oncogene become when it is mutated

Answer 29

oncogene

Question 30

How many copies of a proto-oncogene need to be mutated for uncontrolled division

Answer 30

just one

Question 31

Rb1

Answer 31

tumor repressor gene that contributes to retinoblastoma

Question 32

What would likely lead to cancer? (onco, tumor suppressor)

Answer 32

activation of oncogene, inactivate tumor suppressor