Immune system overview

Question 1

Central (primary) lymphoid organs:

Answer 1

provide the microenvironment for maturation of B and T cells

Question 2

Haematopoietic stem cells are pluripotent, which means they are:

Answer 2

capable of developing into any blood cells

Question 3

Lymphocytes continually recirculate through peripheral lymphoid tissue in order to:

Answer 3

efficiently encounter antigen

Question 4

Peripheral lymphoid organs:

Answer 4

are designed to maximize the contact between antigen and lymphocytes

Question 5

The primary purpose of adaptive immune system is to:

Answer 5

protect from disease upon reinfection with a specific pathogen

Question 6

Rapid but non-antigen specific immune response are produced by the:

Answer 6

Innate immune system

Question 7

Vaccination protects us from inceftious by generating memory:

Answer 7

lymphocytes

Question 8

Which situation describes an example of innate immunity?

Answer 8

Antigen removal by cilia in the respiratory tract

Question 9

The antigen specificity of an adaptive immune response is due to:

Answer 9

activation of antigen-specific lymphocytes

Question 10

Clonal selection results in:

Answer 10

proliferation of antigen-specific lymphocytes

Question 11

Cytokines are NOT:

Answer 11

antigen-specific

Question 12

A fundamental difference in the antigen receptors of B and T cells is:

Answer 12

different requirements for antigen presentation

Question 13

Genes for immunoglobulins (antibodies) are unlike other human genes in that:

Answer 13

gene segments must be spliced together to make each unique antibody molecule

Question 14

Humoral immunity can be acquired passively by:

Answer 14

recieving serum from someone who has recovered from an infection

Question 15

Inflammation does NOT involve:

Answer 15

secretion of antibodies

Question 16

Innate immune responses are most effective against:

Answer 16

common antigens on bacteria

Question 17

Lymphocytes acquire their antigen specificity:

Answer 17

before they encounter antigen

Question 18

A secondary immune response is NOT:

Answer 18

preceded by a longer lag period than a primary response

Question 19

Antibody effector functions include all of the following:

Answer 19

• activating complement on bacterial surfaces to promote phagocytosis by neutrophils
• binding extracellular viruses to block their entry into host cells
• blocking uptake of bacterial toxins by host cells
• coating bacteria to promote their phagocytosis by neutrophils

Question 20

Effector functions of complement include:

Answer 20

• attracting phagocytes to the sites of inflammation
• facilitating phagocytosis of complement-coated bacteria
• increasing blood vessel permeability to plasma proteins
• lysing bacterial cells

Question 21

Jenner observed that milkmaids who were infected with cowpox were later immune to smallpox infections, this is an example of:

Answer 21

memory response to a cross reactive antigen

Question 22

Macrophages generally kill the bacteria they phagocytose by fusing lysosomes containing digestive enzymes with the phagocytic vesicle. In the case of pathogens which block this fusion, pathogen killing can still be achieved through the effector function of:

Answer 22

Th1 cells

Question 23

Phagocytosis can be:

Answer 23

stimulated by antigen binding to complement or antibody

Question 24

Several friends who went on a picnic together developed vomiting and diarrhoea from
eating potato salad contaminated with St. aureus enterotoxin. Effects of the toxin
could best be counteracted by:

Answer 24

antibody binding and neutralizing the toxin

Question 25

These statements are true:

Answer 25

• an example of passive humoral immunity is treatment with horse anti-snake venom
• antigen recognized by helper T cells must be associated with Class II MHC molecules on the surface of professional APC
• each lymphocyte has many antigen binding receptor, each receptor capabler of binding the same antigen
• recognition and killing of virus infected cells by cytotoxic T cells is an example of adaptive immunity