ch.5 | the cell cycle

Question 1

from 5.1

what happens during the G1 stage of the cell cycle?

Answer 1

• cell increases numbers of organelles
• cell increases in size

Question 2

from 5.1

during the _______ stage of the cell cycle, DNA replicates & genetic material is duplicated

Answer 2

S

Question 3

from 5.1

during which stage does the cell prep for division?

Answer 3

G2 stage

Question 4

from 5.1

during the ______ stage, cell division & cytokinesis occurs

Answer 4

M

Question 5

from 5.1

why is apoptosis a necessary process?

Answer 5

it removes unwanted tissue & abnormal cells

Question 6

cyclin is a(n) _____ signal that help control the timing of events in a cell’s life

Answer 6

internal

Question 7

from 5.1

what is mitosis?

Answer 7

division of a cell’s nucleus & genetic material

Question 8

from 5.1

what is the division of the cytoplasm called?

hint: this doesn’t occur in all cells

Answer 8

cytokinesis

Question 9

from 5.1

cells contain _________ that initiate apoptosis. these are usually held in check by inhibitors but can be unleashed by internal or external signals.

Answer 9

enzymes

Question 10

from 5.1

at the end of apoptosis, the cell’s piece are engulfed by __________

Answer 10

white blood cells

Question 11

from 5.2

what are growth factors? where are their signals delivered?

Answer 11

external cell signals that tell the cell whether or not to divide; to the plasma membrae of target cells

Question 12

from 5.2

proto-oncogenes & tumor suppressor genes control what?

Answer 12

a cell’s movement through the cell cycle

Question 13

from 5.2

________________ encode proteins that then promote the cell cycle & prevent apoptosis

Answer 13

proto-oncogenes

Question 14

from 5.2

tumor suppressor genes encode _________ that slow the cell cycle. what do they do to cells in the cell cycle?

Answer 14

proteins; inhibit cells from progressing through the cell cycle

Question 15

from 5.2

mutations in either proto-oncogenes or tumor suppressor genes cause what?

Answer 15

the disruption of normal cell division & behavior

Question 16

from 5.2

a population of divided altered cells is called a ________

Answer 16

tumor

Question 17

from 5.2

what causes cells to stop at
a. checkpoint G1
b. checkpoint G2
c. checkpoint M

Answer 17

a. unfavorable conditions for cell division or DNA damage
b. unfinished DNA replication or DNA damage
c. chromosomes not loned up or not lined up correctly at metaphase plate

Question 18

from 5.2

what is the difference between the function of oncogenes (mutated proto-oncogenes) and that of mutated tumor suppressor genes?

Answer 18

oncogenes encode proteins to over-promote the cell cycle & cause cells to abnormally divide; tumor suppressor genes inhibit the cell cycle, and their mutated forms express proteins that render checkpoints in the cell cycle useless

Question 19

from 5.3

chromatin is a combination of

Answer 19

DNA & protein

Question 20

from 5.2

what are histones

Answer 20

proteins that package DNA to fit into a small space in a cell

Question 21

from 5.3

when a cell isn’t dividing, the chromatin _______ making the DNA available for ________

Answer 21

disperses/extends; gene expression

Question 22

from 5.3

the cell condition in which 2 of each type of chromosome are present is called what?

Answer 22

diploid (2n)

Question 23

from 5.3

what are haploids (1n)

Answer 23

cells w/ half the diploid number that containe only 1 of each type of chromosome

Question 24

from 5.3

during mitosis, the chromosome number ___________

Answer 24

stays constant

Question 25

from 5.3

an aster is an array of short ________ that radiate from the ______________

bonus: plant cells lack _________ which suggests what?

Answer 25

microtubules; centrosome

centrioles: suggests they’re not req’d for spindle formation

Question 26

from 5.3