Antigens

Question 1

Antigens
Every cell in the human body has markers that identify it

Microorganisms (both pathogenic and non-pathogenic), such as bacteria and viruses, also have their own unique markers

These markers are called and what do they allow

Answer 1

antigens (which are macromolecules) and they allow cell-to-cell recognition

Question 2

Antigens are found on

Answer 2

cell surface membranes, bacterial cell walls, or the surfaces of viruses
Some glycolipids and glycoproteins on the outer surface of cell surface membranes act as antigens

Question 3

Antigens can be either

Answer 3

self antigens or non-self antigens

Question 4

Antigens produced by the organism’s own body cells (those that the immune system does not recognise as foreign antigens) are known as

Answer 4

self antigens

Self antigens do not stimulate an immune response

Question 5

Antigens not produced by the organism’s own body cells (those that the immune system recognises as being foreign eg. the antigens found on pathogenic bacteria and viruses or if a person receives a different blood type during a transfusion) are known as

Answer 5

non-self antigens

Non-self antigens stimulate an immune response

Question 6

Antigen Variability
Some pathogens exhibit antigen variability
The antigens present on their surface …………

Answer 6

change frequently due to genetic mutations

Question 7

The antigens present on their surface change frequently due to genetic mutations

This poses a problem for the immune system of many mammal hosts as lymphocytes and memory cells produce a

Answer 7

specific immune response

Question 8

The surface receptors on lymphocytes and memory cells are complementary in shape to

Answer 8

only one antigen

Question 9

When the antigen on a pathogen changes the lymphocytes and memory cells can

Answer 9

no longer attach

Question 10

As a result of antigen variability As a result, there is no ………..

The host gets…………………..

Answer 10

As a result, there is no secondary immune response
The host gets infected and suffers from the disease again

Question 11

The cold virus and flu virus are common pathogens that exhibit antigen variability
Individuals can catch the cold and flu year after year as the antigens on the viruses change and are not recognised by their immune system

Question 12

The different types of pathogen include

Answer 12

viruses, bacteria, fungi and protozoans(protists!