cell cycle check points

Question 1

(Rb, p53, and p21)

Answer 1

Are negative modulators

Question 2

s (Rb, p53, and p21) act primarily at the______and prevent the cell from_______

Answer 2

-G1 checkpoint
-moving forward to division until
damaged DNA is repaired

Question 3

p53 function

Answer 3

halts the cell cycle and recruits’ enzymes to repair damaged DNA

Question 4

; if DNA
cannot be repaired,

Answer 4

p53 triggers apoptosis to prevent duplication

Question 5

Production of p21 is triggered by

Answer 5

p53

Question 6

p21 halts the cycle by binding to and
inhibiting the activity of

Answer 6

Cdk/cyclin complex

Question 7

Retinoblastoma protein: (Rb) is a

Answer 7

group of tumor-suppressor proteins that
regulates the cell cycle by monitoring cell size

Question 8

Somatic P53 mutations occur in almost every
type of cancer at rates from 38%–50%

Answer 8

Ovarian, esophageal, colorectal, head and
neck, larynx, and lung cancer

Question 9

Somatic P53 mutations occur in almost every
type of cancer at rates to about 5% in primary

Answer 9

leukemia, sarcoma, testicular
cancer, malignant melanoma, and cervical
cancer

Question 10

 Many other long-lived mammalian species display cancer resistance

Answer 10

whales, grey squirrels, microbats, cows and horses

Question 11

It’s been found that trunk-swinging creatures have extra copies of a
tumor-suppressing gene

Answer 11

called P53

Question 12

Humans have one P53,; elephants have

Answer 12

20

Question 13

As the cells in an animal’s body divide—human, elephant, or
otherwise—this gene acts like a doctor in charge of genetic triage.

Answer 13

P53