immune system exam qs

Question 1

What is an antigen?

Answer 1

Foreign protein;
(that) stimulates an immune response

Question 2

What is an antibody?

Answer 2

A protein
secreted by plasma cells

Question 3

What is the role of the disulfide bridge in forming the quaternary structure
of an antibody?

Answer 3

Joins two polypeptides;

Question 4

Describe the role of antibodies in producing a positive result in an ELISA
test.

Answer 4

(First) antibody binds to antigen;
2. (Second) antibody with enzyme attached is added;
3. (Second) antibody attaches to antigen;
4. (Substrate/solution added) and colour changes

Question 5

Describe and explain the role of antibodies in stimulating phagocytosis.

Answer 5

Bind to antigen
2. (Antibodies) cause agglutination

Question 6

What is a tumour?

Answer 6

Mass of cells that has formed due to uncontrolled mitosis

Question 7

Describe how the B lymphocytes of a frog would respond to vaccination against Ranavirus.
You can assume that the B lymphocytes of a frog respond in the same way as B
lymphocytes of a human.

Answer 7

B cell (antibody) binds to (viral) specific/complementary
B cell divides by mitosis;
3. Plasma cells release/produce (monoclonal) antibodies

Question 8

  Describe the structure of the human immunodeficiency virus (HIV)

Answer 8

RNA (as genetic material
Reverse transcriptase;
capsid;
attachment proteins

Question 8

Describe how the human immunodeficiency virus (HIV) is replicated once inside helper T
cells (TH cells)

Answer 8

RNA converted into DNA using reverse transcriptase;
2. DNA incorporated/inserted into (helper T cell) DNA/chromosome/genome/nucleus;
3. DNA transcribed into (HIV m)RNA;
4. (HIV mRNA) translated into (new) HIV/viral proteins (for assembly into
viral particles);