Cell Cycle (Q1)

Question 1

What are the two major phases of the cell cycle?

Answer 1

Interphase and Mitotic Phase

Question 2

What is the longest event in the cell cycle?

Answer 2

Interphase

Question 3

Three events that happen during the interphase?

Answer 3

1. Cell grows and makes new copy of DNA
2. Packs nutrients for new daughter cells
3. Duplication of organelles

Question 4

What is the interphase composed of?

Answer 4

G1, S, and G2 phases

Question 5

What does the G in G1 and G2 phases stand for?

Answer 5

Gap or Growth

Question 6

Why were the phases in the interphase called gaps?

Answer 6

They were initially thought to be inactive phases of the cell cycle. Instead, they turned out to be a period for intense metabolic activity.

Question 7

Three events that happen in First Gap/First Growth?

Answer 7

1. Cell growth
2. Duplication of organelles
3. Synthesis of nucleotides

Question 8

How long does the G1 phase take?

Answer 8

5 to 6 hours

Question 9

Two events that happen in Synthesis Phase?

Answer 9

1. DNA replication
2. Duplication of centrosomes (based on Powerpoint)

Question 10

How long does the S Phase take?

Answer 10

10 to 12 hours

Question 11

Three events that happen in Second Gap/Second Growth?

Answer 11

1. Continuation of G1 (growth and organelle duplication)
2. Fills loss energy during S Phase
3. Preparation for next phase

Question 12

This phase makes more proteins for the cell.

Answer 12

G2

Question 13

What is the mitotic phase composed of?

Answer 13

1. Mitosis/Duplication division
2. Cytokinesis

Question 14

Define cytokinesis.

Answer 14

Division of cytoplasm, producing two daughter cells

Question 15

How long does the M Phase take?

Answer 15

Approximately an 1 hour

Question 16

What happens to the two daughter cells produced in one round of the cell cycle?

Answer 16

They may undergo another round of cell division (G1 Phase) or enter a resting state (G0 Phase).

Question 17

Give a list of reasons why cells enter G0 Phase.

Answer 17

1. Unfavorable environmental conditions
2. To restore energy
3. Waiting for signals to enter G1

Question 18

What cells enter a permanent state of G0 Phase?

Answer 18

Mature cardiac muscle cells and nerve cells

Question 19

Why do nerve cells do not divide?

Answer 19

Lack of centrosomes

Question 20

This regulator is constantly synthesized and degraded during cell division.

Answer 20

Cyclin

Question 21

Cyclin is an activating ______ that binds to ______ to form ______.

Answer 21

Cyclin is an activating [protein] that binds to [kinase] to form [CDK-complex].

Question 22

CDK-complex is a type of ______ that ______ or ______ another protein through ______. Gives signals at G1 and G2 checkpoints

Answer 22

CDK-complex is a type of [kinase] that [activates] or [deactivates] another protein through [phosphorylating]. Gives signals at G1 and G2 checkpoints

Question 23

What is phosphorylation?

Answer 23

Process wherein a phosphate group is added to a molecule

Question 24

A regulatory protein responsible for suppressing tumors and repairs damaged DNA

Answer 24

p53

Question 25

What does the p53 do if the damaged DNA is beyond repair?

Answer 25

Triggers apoptosis (cell death)

Question 26

What are the four basic types of cyclin?

Answer 26

G1 cyclin, G1/S cyclin, S cyclin, M cyclin

Question 27

A typical cyclin is present at low levels for most of the cycle but increases strongly at the stage where it's needed. With this, when does G1/S cyclin peak dramatically?

Answer 27

At the transition from G1 to S phase

Question 28

What does the p53 signal to release when DNA damage is detected?

Answer 28

CDK inhibitor

Question 29

Cyclin-dependent kinases bound with M cyclin produces ______.

Answer 29

MPF complexes (maturation-promoting factor)

Question 30

What role does MPF complex play in the cell cycle?

Answer 30

Initiates mitosis

Question 31

When the cyclin in the MPF complex is degraded, what happens to mitosis?

Answer 31

It ends

Question 32

The MPF complex also plays a role in activating another protein complex that is responsible for degrading the M cyclin. What is this protein complex?

Answer 32

APC/C (Anaphase-proposing complex/cyclosome)

Question 33

What are the two specific conditions checked in the G1 Phase checkpoint?

Answer 33

1. Sufficient cell size 2. Intact genetic material

Question 34

What happens if the environment in G1 is not favorable?

Answer 34

1. Delayed progress through G1 2. Enters G0

Question 35

What is the difference between quiescent and senescent cells?

Answer 35

Cells become quiescent because of the lack of nutrition while they become senescent because of aging or deterioration.

Question 36

What happens if the cell's environment is favorable but does not proceed S phase?

Answer 36

The cells differentiate wherein it turns into a more specialized cell.

Question 37

Does the S Phase have a checkpoint?

Answer 37

No.

Question 38

What are the three specific conditions checked in the G2 Phase checkpoint?

Answer 38

1. Sufficient cell size 2. All genetic material is duplicated 3. Intact genetic material

Question 39

What happens if the environment in G2 is not favorable?

Answer 39

Mitosis is delayed

Question 40

What condition is checked in the M Phase checkpoint?

Answer 40

All chromosomes are attached to the spindle fibers.

Question 41

What happens to the M Phase if the chromosomes are not attached to the spindle fibers?

Answer 41

Mitosis halts

Question 42

What could be the result of not having chromosomes attached to the spindles?

Answer 42

Chromosomal syndromes

Question 43

What happens if the control system does not the stop the damaged cell?

Answer 43

Could result in cancer and mutation