Immunology

Question 1

What is the process called when a phagocyte engulfs a pathogen?

Answer 1

Phagocytosis.

Question 2

What happens after a pathogen is engulfed by a phagocyte?

Answer 2

Enters cytoplasm in a vesicle.

Question 3

What fuses with the vesicle containing the pathogen?

Answer 3

Lysosomes.

Question 4

What do lysosomes release to break down the pathogen?

Answer 4

Digestive enzymes.

Question 5

How are waste materials removed from the phagocyte?

Answer 5

By exocytosis.

Question 6

How does a phagocyte destroy a pathogen in blood?

Answer 6

Engulfs it.

Question 7

What forms after the phagocyte engulfs the pathogen?

Answer 7

Vesicle/phagosome that fuses with lysosome.

Question 8

What do lysosome enzymes do to the pathogen?

Answer 8

Digest/hydrolyse.

Question 9

Name two types of cells, other than pathogens, that stimulate an immune response.

Answer 9

Cells from other organisms/transplants; Abnormal/cancer/tumour cells.

Question 10

Name one more cell type that stimulates an immune response.

Answer 10

Cells infected by virus.

Question 11

What do B cells do in the humoral response?

Answer 11

Reproduce by mitosis.

Question 12

What types of cells do B cells produce?

Answer 12

Plasma and memory cells.

Question 13

How does the second infection lead to quicker immunity?

Answer 13

Antibodies produced in larger quantities and quicker.

Question 14

What is the role of the disulfide bridge in antibody structure?

Answer 14

Joins two different polypeptides.

Question 15

How do antibodies stimulate phagocytosis?

Answer 15

Bind to antigen or act as markers.

Question 16

What effect do antibodies have on pathogens?

Answer 16

Cause agglutination (clumping) or attract phagocytes.

Question 17

What does a vaccine contain?

Answer 17

Antigen from pathogen.

Question 18

Which cell presents antigen on its surface after vaccination?

Answer 18

Macrophage.

Question 19

Which cell binds to the antigen presented by macrophage?

Answer 19

T (helper) cell with complementary receptor protein.

Question 20

What does the T helper cell do after binding antigen?

Answer 20

Stimulates B cell.

Question 21

What must the B cell have to be stimulated by T cells?

Answer 21

Complementary antibody on its surface.

Question 22

What happens to B cells after stimulation?

Answer 22

Divide to form clones secreting the same antibody.

Question 23

What do B cells secrete?

Answer 23

Large amounts of antibody.

Question 24

What is one difference between active and passive immunity?

Answer 24

Active involves memory cells; passive does not.

Question 25

Who produces antibodies in active immunity?

Answer 25

Plasma cells/memory cells.

Question 26

Where do antibodies come from in passive immunity?

Answer 26

Introduced from outside/named source.

Question 27

Why is active immunity long term?

Answer 27

Antibodies produced in response to antigen.

Question 28

Why is passive immunity short term?

Answer 28

Antibody given is broken down.

Question 29

Which immunity acts faster?

Answer 29

Passive immunity.

Question 30

What type of genetic material does HIV have?

Answer 30

RNA.

Question 31

What enzyme does HIV carry?

Answer 31

Reverse transcriptase.

Question 32

Name a structural feature of HIV.

Answer 32

Capsomeres/capsid.

Question 33

What covers the HIV virus?

Answer 33

Phospholipid (viral) envelope.

Question 34

What does the HIV envelope come from?

Answer 34

Membrane.

Question 35

What does HIV use to attach to host cells?

Answer 35

Attachment proteins.

Question 36

Name two HIV features not found in bacteria (excluding attachment protein).

Answer 36

Capsid; Reverse transcriptase.

Question 37

Name two more HIV features absent in bacteria.

Answer 37

RNA genome; Envelope.

Question 38

How is HIV replicated inside helper T cells?

Answer 38

RNA converted into DNA by reverse transcriptase.

Question 39

Where is the HIV DNA inserted in the host?

Answer 39

Into helper T cell DNA/chromosome/genome/nucleus.

Question 40

What happens to HIV DNA after insertion?

Answer 40

Transcribed into HIV mRNA.

Question 41

What is produced from HIV mRNA?

Answer 41

New HIV/viral proteins for assembly.

Question 42

How does HIV affect antibody production in AIDS?

Answer 42

Less/no antibody produced.

Question 43

Why does HIV reduce antibody production?

Answer 43

HIV destroys helper T cells.

Question 44

What happens to B cells in AIDS?

Answer 44

Few/no B cells activated or undergo mitosis/differentiate/form plasma cells.

Question 45

How does untreated HIV lead to AIDS?

Answer 45

High viral load increases destruction of helper T/CD4 cells.

Question 46

What is the result of fewer helper T cells?

Answer 46

Less activation of B cells/cytotoxic T cells/phagocytes.

Question 47

What decreases due to fewer plasma cells?

Answer 47

Less production of antibodies.

Question 48

What else is impaired in AIDS?

Answer 48

Ability to kill virus-infected cells and destroy other microbes/cancer cells.

Question 49

Why are some antibodies called monoclonal?

Answer 49

Produced from a single clone of B cells/plasma cells.

Question 50

What else describes monoclonal antibodies?

Answer 50

Produced from the same B cell/plasma cell.

Question 51

Why are monoclonal antibodies specific?

Answer 51

Specific primary structure/order of amino acids.

Question 52

What about monoclonal antibody structure makes them specific?

Answer 52

Specific tertiary/3D shape.

Question 53

What can monoclonal antibodies bind to?

Answer 53

Only one antigen (complementary).

Question 54

What happens in ELISA when the first antibody binds?

Answer 54

Attaches complementary in shape to antigen.

Question 55

What is added after the first antibody in ELISA?

Answer 55

Second antibody with enzyme attached.

Question 56

What does the second antibody do in ELISA?

Answer 56

Attaches to antigen.

Question 57

What happens when substrate is added in ELISA?

Answer 57

Colour changes.

Question 58

Name one aseptic technique when transferring broth to agar.

Answer 58

Keep lid on Petri dish.

Question 59

Why keep Petri dish lid on?

Answer 59

Prevent contamination from unwanted bacteria.

Question 60

Name another aseptic technique.

Answer 60

Wear gloves/mask/wash hands.

Question 61

Why wear gloves/mask/wash hands?

Answer 61

Prevent contamination from bacteria on hands/mouth and prevent spread outside lab.

Question 62

Name a third aseptic technique.

Answer 62

Use sterile pipette/flame loop/flame neck of culture container.

Question 63

Why use sterile tools/flame loops?

Answer 63

Maintain pure culture of bacteria.