Chapter 5 - Defence System

Question 0

EXAM QUESTION

Distinguish between Antigen and Antibody

Answer 0

ANTIGEN - a foreign molecule that stimulates the production of antibodies

ANTIBODY - a protein produced by WBC in response to an antigen.

Question 1

EXAM QUESTION

Name two types of lymphocytes and state a role of each when viruses or other microorganisms enter the blood.

Answer 1

B-cells and T -cells

B CELLS - produce antibodies
T CELLS - recognise and destroy infected or damaged cells

Question 2

EXAM QUESTION

Outline briefly the role of B lymphocytes in the human immune system

Answer 2

Recognise specific antigens on the surface of macrophages

Produce antibodies

Question 3

EXAM QUESTION

Write a note on the role of lymphocytes

Answer 3

Have a major role in the immune system

Two types : B lymphocytes and T lymphocytes

Each B cell produced one type of anyibody

T cells such as Memory T cells stimulate memory B cells to produce antibodies

Question 4

Name the 4 types of T cells

Answer 4

Helper
Killer
Suppressor
Memory

Question 5

Function of Helper T cells

Answer 5

Produce chemicals such as interferon which stimulate the formation of B cells and antibody production.

Stimulate the production of Killer T cells

Question 6

Function of Killer T cells

Answer 6

Produce the protein perforin which forms pores in the membrane of the abnormal cell

This causes the abnormal cell to swell and burst (lysis)

Question 7

Function of Suppressor T cells

Answer 7

Switch off immune response by inhibiting B cells and T cells such as helper cells

Turn off the immune response when infection is over

Question 8

Function of Memory T cells

Answer 8

Stimulate memory B cells to produce antibodies

Others stimulate the production of killer T cells.