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Question 1

Name the two types of lymphocytes.

Answer 1

T lymphocytes and B lymphocytes

Question 2

What response are T lymphocytes involved in?

Answer 2

Cell-mediated response

Question 3

As a general statement, how are lymphocytes able to defend the body?

Answer 3

By being able to distinguish between molecules which are self and non-self.

Question 4

What allows the immune system to identify non-self?

Answer 4

The specific proteins on the pathogens surface.

Question 5

Give two examples of non-specific defence mechanisms.

Answer 5

Physical barrier and phagocytosis.

Question 6

The lymphocyte which fits a specific protein is stimulated to do what?

Answer 6

Divide to build up its numbers to a high level.

Question 7

What is the next line of defence after physical barrier?

Answer 7

Phagocytosis

Question 8

What is the role of the receptors on the cell surface membrane of a phagocyte?

Answer 8

They attach to chemical on the surface of the pathogen.

Question 9

What occurs after phagocytosis?

Answer 9

The primary immune response

Question 10

Define antigen

Answer 10

Any part of an organism that is recognised by the immune system as being non-self.

Question 11

Where are lymphocytes produced and what are they produced by?

Answer 11

In the bone marrow by stem cells

Question 12

Where do B lymphocytes mature?

Answer 12

In the bone marrow

Question 13

What process are B lymphocytes associated with?

Answer 13

The humoral response. (Antibodies)

Question 14

Where do T lymphocytes mature?

Answer 14

In the thymus gland

Question 15

What are cells called which display foreign antigens on their surface?

Answer 15

Antigen-presenting cells

Question 16

What does a phagocyte do after engulfing and breaking down a pathogen?

Answer 16

It displays the antigens from the pathogen on its cell surface membrane.

Question 17

What can T cells do (list 4 things)?

Answer 17

Develop into memory cells, stimulate phagocytosis, stimulate B cells, activate cytotoxic T cells

Question 18

What do cytotoxic T cells do?

Answer 18

They kill cells infected by pathogens.

Question 19

How do cytotoxic T cells kill infected cells?

Answer 19

They produce a protein called perforin which makes holes in the cell membrane.

Question 20

State two differences between a specific and a non specific defence mechanism.

Answer 20

Non-specific mechanisms are quicker and the same response is given for all pathogens.

Question 21

What are commonly used as antigens?

Answer 21

Proteins

Question 22

How do T lymphocytes respond to a phagocyte displaying foreign antigens?

Answer 22

-receptors on a specific helper T cell fit onto these antigens -this attachment causes the T cell to rapidly divide by mitosis

Question 23

How do B cells respond to invading pathogens?

Answer 23

-the antigens of a pathogen are taken up by a B cell -it processes them and displays them in its surface -helper T cells attach to these antigens, activating the B cell -the B cell divides via mitosis producing plasma cells -plasma cells secrete antibodies