Deck 2: Cellular Homeostasis

Question 1

Which cyclin component is predominant in the G1 phase of the cell cycle?

A)Cyclin A
B)Cyclin B1
C)Cyclin E
D)Cyclin D

Answer 1

Cyclin D

Question 2

The point in the cell cycle after which cell division is complete but before the next round of DNA synthesis is:

A)The G2 phase.
B)The G0 phase.
C)The G1 phase.
D)The R phase.

Answer 2

The G1 phase.

Question 3

To be considered a true polymorphism, a SNP must occur with a frequency of:

A)>1%
B)>5%
C)>10%
D)>25%

Answer 3

>1%

Question 4

What protein is responsible for activating phosphorylation of all kinases involved in the cell cycle?

A)Cdk
B)CAK
C)Cyclin
D)Cdk inhibitor

Question 5

Which of the following influences the stability of the mRNA and the efficiency of translation?

A)Introns
B)Untranslated regions
C)Single-nucleotide polymorphisms
D)Exons

Question 6

All of the following are promoters of apoptosis except:

A)BCL-2.
B)Caspases.
C)TNF-alpha.
D)Fas Ligand.

Question 7

The (R) restriction point occurs during what phase in the cell cycle?

A)S
B)G2
C)G1
D)M

Question 8

In which phase of mitosis do the chromosomes align on opposite poles of the cell?

A)Prophase
B)Metaphase
C)Anaphase and telophase
D)Interphase

Question 9

All of the following are mechanisms of apoptosis in hematopoiesis except:

A)Elimination of B cell clonal populations after infection responses.
B)Elimination of PMNs and eosinophils after an inflammatory response.
C)Final stages of RBC maturation.
D)Progression of acute leukemias.

Question 10

The sections of a gene which contain the coding sequences for the final protein product are:

A)Exons.
B)Introns.
C)UTRs.
D)Nucleosomes.

Question 11

Which phospholipids are predominantly found in the inner layer of the lipid bilayer?

A)PE and PC
B)PE and PS
C)PS and SM
D)PC and SM

Question 12

The plasma membrane of blood cells is characterized by which of the following?

A)Carbohydrate components (of glycolipids, glycoproteins) embededed in the lipid bilayer
B)The asymmetric distribution of the phospholipids
C)The hydrophilic ends of the phospholipids directed toward the inside of the lipid bilayer
D)The absence of peripheral proteins

Question 13

Which cytoplasmic organelle's function is lipid synthesis?

A)Smooth endoplasmic reticulum
B)Golgi apparatus
C)Mitochondria
D)Ribosomes

Question 14

Protein synthesis occurs predominantly in the:

A)Cell membrane.
B)Nucleus.
C)Lysosome.
D)Cytosol.

Question 15

In which phase of the cell cycle is a cell quiescent?

A)The G1 phase
B)The G0 phase
C)The R phase
D)The S phase

Question 16

Structurally abnormal proteins can be eliminated from the body by tagging them with _________ and sending them to the __________.

A)Caspase; apoptosis pathway
B)Ubiquitin; proteosome
C)Cyclins; necrosis pathway
D)CDKs; apoptosis pathway

Question 17

Which phospholipids are found predominantly in the outer layer of the lipid bilayer?

A)Phosphatidylethanolamine and phosphatidylserine
B)Phosphatidylethanolamine and phosphatidylcholine
C)Phosphatidylserine and sphingomyelin
D)Phosphatidylcholine and sphingomyelin

Question 18

If an organism fails to regulate apoptosis, resulting in excessive apoptosis, which of the following processes might result?

A)Neurodegenerative disorder
B)Autoimmune disorder
C)Lymphoma
D)Carcinoma

Question 19

Apoptosis play an role in human development in all of the following except:

A)Removal of interdigital webs of the hands and feet.
B)Formation of the blood vessels and the gastrointestinal tract.
C)Differentiation (divergence) of mast cells and basophils.
D)Selection of appropriate T and B lymphocyte clones.

Question 20

In order to maintain ________, terminally differentiated blood cells undergo _________.

A)Cell cycle division; necrosis
B)Tumor suppression; apoptosis
C)Homeostasis; apoptosis
D)Cell regeneration; necrosis

Question 21

Describe the apoptotic pathway.

Question 22

Predict the effect of p16 on the cell cycle of dividing cells.

A)Increased cell cycle progression
B)Decreased cell cycle progression
C)No change in the cell cycle progression
D)Initiate apoptosis

Question 23

Which regulatory protein is present in all stages of the cell cycle but has varying degrees of phosphorylation (activation) from phase to phase?

A)p53
B)Rb protein
C)p21
D)Cyclin D

Question 24

What feature distinguishes necrosis from apoptosis?

A)Necrosis requires ATP.
B)Necrosis is characterized by cellular shrinkage and chromatin condensation.
C)Necrosis induces inflammation.
D)Necrosis results in nuclear fragments of 185 base pairs.

Question 25

Explain in detail how p53 and Rb can contribute to the onset of malignancy.

Question 26

UTRs constitute which segments of mRNA?

A)Exons
B)Introns
C)3' and 5' ends
D)Heteronuclear RNA

Question 27

Predict the effect of the Bax:Bcl-2 complex on the apoptotic pathway.

A)The pathway is activated by Bax: Bcl-2.
B)The pathway is inhibited by Bax: Bcl-2.
C)The pathway is not affected by Bax: Bcl-2.
D)The pathway will be activated and then inhibited by Bax:Bcl-2.

Question 28

Explain the role of epigenetic alterations in cancer development.

Question 29

Disposal of damaged or misfolded proteins is carried out by which cell component?

A)Lysosome
B)Ubiquitin/proteosome system
C)Caspase/apoptosis system
D)Molecular chaperones

Question 30

Which of the following are apoptosis activators?

A)BCL-2
B)Mcl-1
C)Bcl-XL
D)Bak

Question 31

Exposure to radiation would lead to activation of which caspase pathway?

A)Extrinsic pathway
B)Intrinsic pathway
C)Common pathway
D)None of the above

Question 32

Initiation of apoptosis occurs primarily with:

A)Activation of p53.
B)Cleavage of appropriate caspases at timely intervals.
C)Stimulus from an inflammatory response.
D)Activation of BCL-2.

Question 33

Which two proteins are critical for the effective function of the G1 checkpoint?

A)Cdk4 and Cdk6
B)Cyclin E
C)P21 and p57
D)P53 and Rb

Question 34

Cdk or kinase must be complexed with what molecule to drive one cell to the next cell-cycle stage?

A)DNA
B)Phosphorylating enzymes
C)mRNA
D)Cyclin

Question 35

Malignancies can result from which of the following?

A)Accelerated apoptosis
B)Inhibited apoptosis
C)Normal occurrence of apoptosis
D)None of the above

Question 36

List the four major phospholipids found in the plasma membrane of hematopoietic cells, and explain their unique distribution.

Question 37

Clearance of cytotoxic T cells after an immune response results from:

A)Accelerated apoptosis.
B)Inhibited apoptosis.
C)Normal occurrence of apoptosis.
D)None of the above.

Question 38

At which checkpoint would detection of unreplicated DNA strands occur?

A)G1 checkpoint
B)G2/M checkpoint
C)S phase checkpoint
D)Metaphase checkpoint

Question 39

All of the following are potential proto-oncogenes except:

A)Proteins that function as growth factor receptors.
B)Proteins that bind DNA.
C)Growth factors.
D)Proteins that neutralize growth factor receptors.

Question 40

List three ways in which the caspase pathway can be activated.Explain the role of each, and also indicate which arm of the caspase pathway will be activated.