Cell Biology Lectures 21-22 (Part 2)

1.

1 point

Cells go into S phase if nutrient conditions are poor

True

False

2.

1 point

Which one is not one of the 6 stages of M phase?

Prophase

Prometaphase

Metaphase

Ametaphase

Anaphase

Telophase

Cytokenisis

3.

1 point

Chromosomes would be pulled apart, even if they are not all attached to the mitotic spindle

True

False

4.

1 point

Apoptosis depends on a tightly regulated proteolytic cascade.

True

False

5.

1 point

Nuclear division is called _______ while cytoplasmic division is called ________.

Mitosis - Cytokinesis

Resting Phase - Cytokinesis

Cytokinesis - Resting Phase

Mitosis - Resting Phase

6.

1 point

Inactivation of p27 (a CKI) promotes aberrant cell growth and thus cancer.

True

False

7.

1 point

Cdks are gradually activated upon the gradual increase in cyclin expression.

True

False

8.

1 point

Cells go into M phase if DNA is not fully replicated

True

False

9.

1 point

Which of the following is not one of the 4 phases of the cell cycle?

S Phase

G1 Phase

G0 Phase

G2 Phase

M Phase

10.

1 point

All CDKs phosphorylate the same substrates.

True

False

11.

1 point

Interphase is composed of?

G0 Phase

Resting Phase

M Phase

G1 Phase

G2 Phase

S Phase

12.

1 point

p53 inactivation promotes cancer.

True

False

13.

1 point

The Cell Division Cycle (Which one is false

Cells can produced without the assistance other cell

Cells reproduce by repeated rounds of cell growth and division

Requires DNA replication and segregation

Requires duplication of organelles and macromolecules (in most cases)

14.

1 point

What compacts chromatids?

Mitotic spindle

Contractile ring

Condensins

None of the above

15.

1 point

Cell growth, unlike cell proliferation, does not depend on the cell-cycle control system.

True

False

16.

1 point

Which is the longest phase of the cell cycle for this population of cells?

M Phase

G1 Phase

S Phase

G2 Phase

17.

1 point

What is/are the stage that cells can go into to withdraw from the cell cycle?

Withdraw to G0

Withdraw permanently

Terminally differentiate

All of the above

18.

1 point

Many cells in normal animal tissues require extracellular signals from other cells to avoid apoptosis. This could be a mechanism for ensuring that cells only survive when and where they are needed.

True

False

19.

1 point

M phase is triggered by?

Chromosome division

Division of the cytoplasm

Activation of the phosphate Cdc25 and M-CDK

None of the above

20.

1 point

Distinct cyclin-CDK complexes trigger distinct phases of the cell cycle

True

False

21.

1 point

Is cell division responsive to signals from other cells?

Yes

No

22.

1 point

What is duplicated in S phase?

CKI

p53

Tubulins

DNA

23.

1 point

When DNA is damaged or incompletely or incompletely replicated, what is inhibited to stall the cell in G2 and thus block progression into M phase?

S-CDK

Origins of replication

CDC-25

S-CDC

24.

1 point

Where does replication begin on chromosomes?

Origins of replication

S-CDK

CDC-25

S-CDC

25.

1 point

External signals can stimulate apoptosis by activating a set of cell-surface receptors known as:

death receptors.

Bax receptors.

suicide receptors.

caspase receptors.

26.

1 point

Which of the following statements describe how growth factors stimulate animal cell enlargement?

They stimulate intracellular protein synthesis.

They stimulate DNA replication.

They stimulate microtubule polymerization.

They stimulate an influx of extracellular water into the cytosol.

27.

1 point

Which of the following statements are is false?

Bax and Bak are death-promoting members of the Bcl2 family that induce the release of cytochrome c from mitochondria into the cytosol.

The death-promoting members of the Bcl2 family include Bcl2 itself.

Some Bcl2 family members promote apoptosis, whereas others inhibit apoptosis.

Some death-inhibiting members of the Bcl2 family inhibit apoptosis by blocking cytochrome c release from mitochondria.

28.

1 point

What does not happens in M phase?

Chromosome division

Division of the cytoplasm

Activation of the phosphate Cdc25 and M-CDK

None of the above

29.

1 point

Cells that have left the cell cycle are in a phase called

G2 Phase

S Phase

G1 Phase

G0 Phase

Resting Phase

M Phase

30.

1 point

Cancer cells fail to obey normal “social” controls on cell behavior and therefore outgrow, out-divide and out-survive their normal neighbors.

True

False

31.

1 point

The cell cycle time of mammalian fibroblasts is?

About 12 hours

About 24 hours

About 36 hours

None of the above

32.

1 point

What “pulls the trigger” for replication initiation?

S-CDC

S-CDK

Origins of replication

CDC-25

33.

1 point

Where is entry into the cell cycle regulated?

G1-S Transition

S-G2 Transition

G2-M Transition

M-G1 Transition

34.

1 point

All present-day cells have arisen by an uninterrupted series of cell divisions extending back in time to the first cell division

True

False

35.

1 point

What is a pathway that senses DNA damage?

p53

CKI

CKD

p52

36.

1 point

Survival factors act primarily by stimulating cell division.

True

False

37.

1 point

In prometaphase disassembly of nuclear envelope and spindle microtubules capture replicated chromosomes

True

False

38.

1 point

Which phase of the cell cycle is shortest?

G1 Phase

M Phase

S Phase

G0 Phase

G2 Phase

39.

1 point

How do cells turn off the cell cycle after mitosis?

Degrade cyclins

Block cyclins synthesis

Express CKIs

All of the above

40.

1 point

What is the protein complex that ubiquitylates M and S cyclins?

ABC

CDK

APC

PCK

41.

1 point

Which of the following statements describes how mitogens operate?

They directly phosphorylate and activate Cdks.

They suppress apoptosis.

They overcome the intracellular braking mechanisms that tend to block progression through the cell cycle.

42.

1 point

Commitment to M phase is ensured by negative feedback by M-Cdk?

True

False

43.

1 point

CDKs must be bound to _______for activity

Polyubiquilytation

Cyclins

Spindle

Microtubules

44.

1 point

Apoptosis is a form of programmed cell death, in which cells kill themselves by migrating to the blood stream where they are carried to the liver for destruction.

True

False

45.

1 point

What would happen to a person if all cell division was halted? (Which one is not true?)

The person would die in a couple of days

The dead cell in the body won't be replaced

Cell would replicate but at a slower pace

DNA won't be able to replicate any longer

46.

1 point

Dephosphorylated Rb promotes the cell cycle.

True

False

47.

1 point

What in the cell must divide with each cell cycle?

DNA

Organelles

Macromolecules

All of the above

48.

1 point

Cyclins are inactivated by

Microtubules followed by degradation

Spindle followed by degradation

Polyubiquilytation followed by degradation

CDK followed by degradation

49.

1 point

When a cell is acutely injured, it usually dies by:

necrosis.

apoptosis.

phagocytosis.

endocytosis.

50.

1 point

Which is not one of the 2 cytoskeletal machines that carry out mitosis and cytokinesis are:

Mitotic spindle

Contractile ring

Condensins

None of the above