Unit 1 Cell cycle

Question 1

What are the 2 major phases of the cell cycle?

Answer 1

mitotic phase

interphase

Question 2

interphase

Answer 2

G1
S
G2

Question 3

G1 phase

Answer 3

gap 1, presynthetic; variable in length
cell growth; histones made
protein synthesis
checkpoint prior to S phase

Question 4

G0 phase

Answer 4

in cells that can exit the cycle for varying lengths

cardiac and neurons exit permanently, hepatocytes around a year

Question 5

S phase

Answer 5

DNA synthesis
6-8 hrs
semiconservative replication maintains DNA integrity
centrioles replicated

Question 6

G2 phase

Answer 6

gap 2 or post synthetic; relatively uniform in length, 3-6h
preparation for mitosis
checkpoint for DNA repair

Question 7

M phase

Answer 7

mitotic phase; relatively uniform in length; 1-2h

Question 8

external cycle regulation

Answer 8

growth factors

1. bind to specific receptors
2. send cytoplasmic signals to cellular components

Question 9

internal cycle regulation

Answer 9

cyclins

maturation promoting factor

Question 10

cyclins

Answer 10

bind to specific kinases (cyclin-dependent kinases CKDS) to regulate events of interphase; concentration increases through interphase

Question 11

maturation promoting factor (MPF)

Answer 11

aka MCDK; mitotic cyclin plus kinase; rapid increase in concentration triggers cell entry into mitosis

Question 12

mitosis

Answer 12

cell division = karyokinesis

Question 13

karyokinesis

Answer 13

nuclear division

Question 14

phases of mitosis

Answer 14

prophase
metaphase
anaphase
telophase

Question 15

prophase

Answer 15

1. chromatin condenses, chromosomes seen
2. nuclear envelope breaks down
3. centrosomes separate to opposite poles
4. microtubules generated connecting centrioles to chromosomes

Question 16

metaphase

Answer 16

1. chromosomes condense further and attach to mitotic spindle at kinetochores
2. chromosomes are moved to align at equatorial plane

Question 17

kinetochores

Answer 17

large electron dense protein complexes at centromere

Question 18

anaphase

Answer 18

sister chromatids separate and move to opposite poles

Question 19

telophase

Answer 19

nuclear envelope regenerated; chromosomes disperse

Question 20

cytokinesis

Answer 20

division of cytoplasm

1. band of action filaments form at equatorial plane
2. constriction of band separates cytoplasm
3. occurs during anaphase and completed during telophase

Question 21

apoptosis

Answer 21

programmed cell death
kills old, damaged, infected, unneeded, abnormal cells
cells shrink, detach, round-up
froms blebs; release chemoattractants to stimulate phagocytosis

Question 22

embryonic apoptosis

Answer 22

normal reorganization of tissues

Question 23

adult apoptosis

Answer 23

balance cell divisions

does not initial inflammatory response