Specific Cellular Defences Against Pathogens 3.6

Question 1

What are lymphocytes

Answer 1

A type of white blood cell

Question 2

How are lymphocytes specific

Answer 2

They have a single type of membrane receptor

Question 3

How do lymphocytes respond to specific pathogens

Answer 3

The membrane receptor is specific for one antigen on the invading pathogen

Question 4

What is an antigen

Answer 4

A type of protein found on the surface of pathogens

Question 5

What is clonal population

Answer 5

Multiple of the same lymphocyte is produced

Question 6

What happens to the cells from the clonal population

Answer 6

Some are used immediately and others are kept for memory cells for future use

Question 7

What are the two types of lymphocytes

Answer 7

B lymphocytes and T lymphocytes

Question 8

What do B lymphocytes do and what happens to dead pathogens

Answer 8

Produce antibodies which bind to antigens inactivating the pathogen and the dead pathogen can be destroyed by phagocytes

Question 9

4 ways in which antibodies inactivate pathogens

Answer 9

Have specific binding site
Bind to antigen
Released by B lymphocytes
Flag them for destruction by phagocytes

Question 10

What is the negative thing about B lymphocytes

Answer 10

Can respond to antigens on substances that are harmless to the body (hypersensitivity) resulting in an allergic reaction

Question 11

What are T lymphocytes

Answer 11

Destroy infected body cells by recognising antigens of the pathogen on the membrane and inducing apoptosis

Question 12

What is apoptosis

Answer 12

T-lymphocytes attach onto infected cells abdominal release proteins. These proteins diffuse into infected cells causing the cells to self destruct using enzymes. The remains of the cells are engulfed by phagocytes

Question 13

Why is it important that T lymphocytes have specific surface proteins

Answer 13

To allow them to distinguish between the self antigens and non self antigens on its surface

Question 14

Why is the ability to distinguish between self and non self antigens important

Answer 14

Incase the wrong cells get destroyed which will cause an autoimmune disease

Question 15

What will happen if the immune system regulation failure leads to the T lymphocytes immune response to self antigens

Answer 15

They will attack the bodys own cells resulting in auto immune diseases such as type 1 diabetes and rheumatoid arthritis

Question 16

3 reasons memory cells are beneficial

Answer 16

Response happens much more rapid
Theres a higher concentration
Response is maintained for a longer time

Question 17

How does HIV attack the immune system

Answer 17

HIV attacks and destroys T lymphocytes. HIV causes depletion of T lymphocytes which leads to the development of AIDs

Question 18

How does AIDs cause infections

Answer 18

Individuals with AIDs have a weakened immune system and so are more vulnerable to opportunistic infections