Cell Cycle Control

Question 1

Cell cycle

Answer 1

Interphase (90%) + mitotic phase

Question 2

Interphase

Answer 2

G1 phse
S phase
G2 phase

Question 3

Type of cells in cell cycle

Answer 3

1)Labile cells(Proliferative cell)
2)Stable cells
3)Permanant cells

Question 4

Labile cells

Answer 4

Proliferative cells
-Epithelium of skin,GI tract & uninary tract
-Hematopoietic stem cells in bone marrow

Question 5

Stable cells

Answer 5

Enter the cell division when needed like wound
-Liver cells (Hepatocytes)
-Epithelium of kidney tubules

Question 6

Permanant cells

Answer 6

Amitotic cells
-Neurons
-Skeletal muscle
-Cardiac muscle

Question 7

Permanant cells spend all of their time in ______ of cell cycle

Answer 7

G0 phase of cell cycle

*Simply living & serving its function without preparation for cell division

Question 8

G1 phase or pre synthetic gap

Answer 8

-Production of protein & organelles
-Increase the cell size

Question 9

S phase or synthetic phase

Answer 9

-DNA replication
-Centrosome replication

Question 10

Cells entering the G2 phase contains

Answer 10

Twice as much DNA than in G1

Question 11

G2 phase or post synthetic phase

Answer 11

-Check replicated DNA
-Check cell contents

Question 12

M phase

Answer 12

Mitosis + cytokinesis

Question 13

Cell cycle is regulated at ________.

Answer 13

at check-points by external & internal signals

Question 14

Checkpoint in cell cycle

Answer 14

A control point where stop & go signals that regulate the cell cycle
1)G1 checkpoint
2)G2 checkpont
3)M chekpoint

Question 15

G1 check point

Answer 15

Checkpoint between G1 & S phase also known as restriction point
Main protein-p53
-check the condition of DNA for replication

Question 16

Main protein of G1 checkpoint

Answer 16

p53

Question 17

G1 checkpoint is also known as

Answer 17

Restriction point

Question 18

Most common gene mutation found in cancer is

Answer 18

Gene TP53 that produces p53

Question 19

Function of TP53

Answer 19

Production of p53 proteins for G1 checkpoint

Question 20

G2 checkpoint

Answer 20

Checkpoint between G2 & M phase
-check the cell size and organelles have been properly replicated to support 2 daughter cells

Question 21

Main protein for G2 checkpoint

Answer 21

p53
also MPF

Question 22

What will happen if the cell didn’t receieve go single from G1 checkpoint?

Answer 22

Cell will enter the G0 phase until the DNA is repaired.

Question 23

M checkpoint

Answer 23

Checkpoint during Metaphase
-check all chromosomes are properly aligned at the metaphase plate
-each kinetochore is correctly attached to spindle fibers from opposite poles

Question 24

When will happen if the cell fail to pass the M checkpoint?

Answer 24

Cell stops progression to anaphase in order to prevent incorrect chromosome separation(aneuploidy)

Question 25

M checkpoint is also known as

Answer 25

Spindle check point

Question 26

Checkpoint b/w anaphase & telophase

Answer 26

Check the anaphase is completed & all chromosomes are well separated before cytokinesis begins

Question 27

Cell cycle regulatory molecules

Answer 27

Protein kinase & cyclins

Question 28

Protein kinase

Answer 28

Enzymes that activate or inactivate other proteins by phosphorylating

Question 29

Kinase that regulate the cell cycle present in _______ & in _______ form.

Answer 29

Constant concentration Inactive form

Question 30

How kinase is activated?

Answer 30

In order to activate,kinase must be attached to cyclin(protein)

Question 31

Activity of Cyclin-dependent kinase or Cdks during cell cycle

Answer 31

Changes with the concentration of its cyclin partner

Question 32

Kinase of the cell cycle are also known as

Answer 32

Cyclin-dependent kinase or Cdks

Question 33

Cyclin is synthesized during ______ .

Answer 33

late S phase throughout the G2 phase

Question 34

Cyclin+Cdk

Answer 34

MPF (maturation promoting factor or M phase promoting factor)

Question 35

Function of MPF

Answer 35

Promote mitosis by phosphrylating multiple proteins

Question 36

What will happen when MPF reach anaphase?

Answer 36

At anaphase,cyclin of MPF degrades and terminate M phase and cell enter G1 phase At G1 phase,Cdk is recycled

Question 37

MPF activity is peak at

Answer 37

Metaphase

Question 38

Cyclin concentration peak at

Answer 38

S phase & G2 phase,M phase

Question 39

MPF controls the cell's passage mainly

Answer 39

through the G2 checkpoint

Question 40

How internal & external signal control the cell cycle?

Answer 40

By controlling the cell division through cell cycle control molecules

Question 41

Internal signal of cell cycle

Answer 41

Internal signal at M checkpoint -Anaphase do not begin until all chromosomes are properly attached to spindle at metaphase plate -If all are attached,cyclin-CDK complex activates enzyme Separase -Separase cleaves the cohesin>sister chromatids separate

Question 42

External signal of cell cycle

Answer 42

1)Density dependent inhibition 2)Anchorage dependent inhibition

Question 43

Cell must be attached or anchored to certain surfaces like ECF & basement membrane in order to divide.True or False?

Answer 43

True

Question 44

Cell density is limited by

Answer 44

a single layer *normal cells stop dividing if a single layer is fully packed

Question 45

Cancer cells do not exhibit

Answer 45

Anchorage dependence & density-dependent inhibition *Cancer cells continue to divide well beyond a single layer limit

Question 46

Normal cells require _______ in order to undergo cell division.

Answer 46

Growth factor

Question 47

Cancer cells do not require _______ in order to undergo cell division.

Answer 47

Growth factor *They can even produce growth factor own their own

Question 48

Cyclin synthesized in _____ & accumulate in ______.

Answer 48

S phase G2 phase

Question 49

Most important checkpoint

Answer 49

G1 checkpoint

Question 50

G1 checkpoint mainly focus on

Answer 50

Nutrient DNA damage Cell size Growth factor

Question 51

G2 checkpoint mainly focus on

Answer 51

DNA damage DNA replication completeness

Question 52

M checkpoint mainly focus on

Answer 52

Chromosome attachment to spindle fiber at metaphase plate