Chapter 10.6: Control of the Cell Cycle

Question 1

Define G₂/M checkpoint

Answer 1

the second cell-division control point, at which division can be delayed if DNA has not been properly replicated or is damaged

Question 2

Define  Cyclin-Dependent Kinase (Cdk)

Answer 2

any of a group of protein kinase enzymes that control progress through the cell cycle. These enzymes are only active when complexed with cyclin. The cdc2 protein, produced by the cdc2 gene, was the first Cdk enzyme discovered

Question 3

What is the third cell-division checkpoint, at which all chromosomes must be attached to the spindle. Passage through this checkpoint commits the cell to anaphase?

Answer 3

 Late Metaphase (the spindle checkpoint)

Question 4

Define p53 gene

Answer 4

the gene that produces the p53 protein that monitors DNA integrity and halts cell division if DNA damage is detected. Many types of cancer are associated with a damaged or absent p53 gene

Question 5

What is any of a group of protein kinase enzymes that control progress through the cell cycle. These enzymes are only active when complexed with cyclin. The cdc2 protein, produced by the cdc2 gene, was the first Cdk enzyme discovered?

Answer 5

 Cyclin-Dependent Kinase (Cdk)

Question 6

Define G₁/S checkpoint

Answer 6

the primary control point at which a cell “decides” whether or not to divide. Also called START and the restriction point

Question 7

Define • Anaphase-Promoting Complex (APC)

Answer 7

a protein complex that triggers anaphase; it initiates a series of reactions that ultimately degrades cohesion, the protein complex that holds the sister chromatids together. The sister chromatids are then released and move toward opposite poles in the cell.

Question 8

Define  Late Metaphase (the spindle checkpoint)

Answer 8

the third cell-division checkpoint, at which all chromosomes must be attached to the spindle. Passage through this checkpoint commits the cell to anaphase

Question 9

What is the unrestrained growth and division of cells; it results from a failure of cell division control?

Answer 9

cancer

Question 10

What is the primary control point at which a cell “decides” whether or not to divide. Also called START and the restriction point?

Answer 10

G₁/S checkpoint

Question 11

What is any of a number of proteins that are produced in synchrony with the cell cycle and combine with certain protein kinases, the cyclin-dependent kinases, at certain points during division?

Answer 11

cyclins

Question 12

What is a mutant form of a growth-regulating gene that is inappropriately “on”, causing unrestrained cell growth and division?

Answer 12

oncogene

Question 13

Define oncogene

Answer 13

a mutant form of a growth-regulating gene that is inappropriately “on”, causing unrestrained cell growth and division

Question 14

What is the gene that produces the p53 protein that monitors DNA integrity and halts cell division if DNA damage is detected. Many types of cancer are associated with a damaged or absent p53 gene?

Answer 14

p53 gene

Question 15

What is a gene that, when mutated, predisposes individuals to a rare form of cancer of the retina; one of the first tumor-suppressor genes discovered?

Answer 15

• Retinoblastoma Susceptibility Gene (Rb)

Question 16

What is a gene that normally functions to inhibit cell division; mutated forms can lead to the unrestrained cell division of cancer, but only when both copies of the gene are mutant?

Answer 16

tumor-suppressor gene

Question 17

Define tumor-suppressor gene

Answer 17

a gene that normally functions to inhibit cell division; mutated forms can lead to the unrestrained cell division of cancer, but only when both copies of the gene are mutant

Question 18

Define cancer

Answer 18

the unrestrained growth and division of cells; it results from a failure of cell division control

Question 19

What is a protein complex that triggers anaphase; it initiates a series of reactions that ultimately degrades cohesion, the protein complex that holds the sister chromatids together. The sister chromatids are then released and move toward opposite poles in the cell?

Answer 19

• Anaphase-Promoting Complex (APC)

Question 20

What is the second cell-division control point, at which division can be delayed if DNA has not been properly replicated or is damaged?

Answer 20

G₂/M checkpoint

Question 21

What is a normal cellular gene that can act as an oncogene when mutated?

Answer 21

proto-oncogene

Question 22

Define • Retinoblastoma Susceptibility Gene (Rb)

Answer 22

a gene that, when mutated, predisposes individuals to a rare form of cancer of the retina; one of the first tumor-suppressor genes discovered

Question 23

What is a Cdk enzyme active at the G₂/M checkpoint?

Answer 23

M Phase-Promoting Factor (MPF)

Question 24

Define M Phase-Promoting Factor (MPF)

Answer 24

a Cdk enzyme active at the G₂/M checkpoint

Question 25

Define proto-oncogene

Answer 25

a normal cellular gene that can act as an oncogene when mutated

Question 26

Define cyclins

Answer 26

any of a number of proteins that are produced in synchrony with the cell cycle and combine with certain protein kinases, the cyclin-dependent kinases, at certain points during division