Part 4

Question 1

Where do lymphoid progenitor cells migrate?

Answer 1

Thymus

Question 2

What percentage of thymocytes pass the tests in the thymus?

Answer 2

Minority

Question 3

What is the fate of thymocytes that fail the thymus tests?

Answer 3

Eliminated

Question 4

What occurs during TCR gene rearrangement?

Answer 4

TCR gene splicing

Question 5

What do double-positive T cells express?

Answer 5

CD4 and CD8

Question 6

How is TCR gene rearrangement similar to another immune process?

Answer 6

Antibody rearrangement

Question 7

What do double-positive T cells differentiate into?

Answer 7

CD4+ or CD8+ T cells

Question 8

What type of MHC do CD8+ T cells recognize?

Answer 8

MHC Class I

Question 9

What type of MHC do CD4+ T cells recognize?

Answer 9

MHC Class II

Question 10

What is required for T-cell activation?

Answer 10

Co-stimulatory signals

Question 11

What cells present antigens to naive T cells?

Answer 11

Dendritic cells

Question 12

Where do naive T cells survey for antigens?

Answer 12

Lymph nodes

Question 13

What is the role of CD8+ cytotoxic T cells?

Answer 13

Killing infected cells

Question 14

How do CD4+ helper T cells aid immune responses?

Answer 14

Secreting cytokines

Question 15

What is the function of regulatory T cells?

Answer 15

Inhibit immune responses

Question 16

Which cytokines promote Th1 differentiation?

Answer 16

IL-12 & IFN-y

Question 17

Which cytokine promotes Th2 differentiation?

Answer 17

IL-4

Question 18

What does IL-17 recruit in Th17 responses?

Answer 18

Neutrophils

Question 19

What do CD8+ T cells express after activation?

Answer 19

Fas-ligand

Question 20

Which receptor does Fas-ligand bind on infected cells?

Answer 20

CD95

Question 21

What is the final step in the killing process by CD8+ T cells?

Answer 21

Apoptosis

Question 22

What is the first antibody produced by B cells?

Answer 22

IgM

Question 23

Where does affinity maturation occur?

Answer 23

Germinal centers

Question 24

What is the function of IgE?

Answer 24

Activates eosinophils and mast cells

Question 25

What is the first phase of T cell response?

Answer 25

Antigen recognition

Question 26

What does clonal expansion lead to?

Answer 26

Germinal center formation

Question 27

What cells are formed in the effector phase?

Answer 27

Cytotoxic T Lymphocytes (CTLs)

Question 28

What is the function of IgG in neutralization?

Answer 28

Binds to toxins or pathogens

Question 29

What does opsonization involve?

Answer 29

Coating bacterial surfaces for phagocytes

Question 30

What immune cells are involved in ADCC?

Answer 30

NK cells

Question 31

Where does central tolerance occur?

Answer 31

Thymus or bone marrow

Question 32

What happens to self-reactive T cells in the thymus?

Answer 32

Apoptosis

Question 33

What protein is involved in peripheral tolerance?

Answer 33

CTLA-4

Question 34

What is the role of Tregs in immune tolerance?

Answer 34

Suppress other lymphocytes

Question 35

What happens when T cells recognize self-antigens?

Answer 35

Anergy

Question 36

What cytokines do Tregs secrete?

Answer 36

IL-10 & TGF-β

Question 37

Which receptors decrease on T cells during migration?

Answer 37

CCR7

Question 38

Where do T cells and B cells meet?

Answer 38

Edges of lymphoid follicles

Question 39

Which receptor increases on T cells in the follicles?

Answer 39

CXCR5

Question 40

How many autosomes are in human cells?

Answer 40

44

Question 41

Which region of chromosomes is gene-rich?

Answer 41

Euchromatic regions

Question 42

What process causes chromosome breakage?

Answer 42

Translocation

Question 43

Which radical is the most reactive?

Answer 43

Hydroxyl radical

Question 44

What proteins help with metal sequestration?

Answer 44

Albumin, transferrin

Question 45

Which antioxidant enzyme converts superoxide into hydrogen peroxide?

Answer 45

Superoxide dismutase