B Cells and T Cells - 11/12/23

Question 1

What is a lymphocyte?

Answer 1

A type of WBC that is specific to a pathogen

Question 2

What is a Self-Antigen?

Answer 2

An antigen that belongs to the body’s cells and isn’t foreign

Question 3

What is an Antigen made of?

Answer 3

glycoprotein or glycolipid

Question 4

How many lymphocytes are in the body? And what do they recognise?

Answer 4

• Over 10 million
• A different antigen shape

Question 5

Why is foetal infection rare?

Answer 5

There is a physical barrier preventing blood mixing

Question 6

What are properties of B lymphocytes? [2]

Answer 6

• It becomes mature in bone marrow
• Involved in humoural response - releasing antibodies into body fluids

Question 7

Where does B-Lymphocytes mature?

Answer 7

Bone Marrow

Question 8

What are properties of T-Lymphocyte cells? [2]

Answer 8

• It becomes mature in Thymus gland (moves to here from bone marrow)
• Involved in cell-mediated immunity involving body cells

Question 9

Where do T-Lymphocytes mature?

Answer 9

In Thymus gland

Question 10

Explain Cell Mediated Immunity. [2]

Answer 10

• When you respond to cells in own body that’s been infected by non-self pathogens (or cells from same species)
• Because the cells are genetically different - they have different antigens on cell surface

Question 11

What are the different types of T-Cells?

Answer 11

1. Killer T Cell
2. Helper T Cell
3. Memory T Cell
4. Supressor T Cell

Question 12

What do Killer T Cells do?

Answer 12

Destroy pathogen infected cells

Question 13

What does Helper T Cells do? [2]

Answer 13

• Boosts immune response by:
• Stimulating B-Cells to make antibodies
• Activate killer T Cells to divide

Question 14

What does Memory T Cell do?

Answer 14

Remembers antigen for protection in future infections

Question 15

What are examples of the specific cells that T-Lymphocyte cells target?

Answer 15

1. Phagocytes/macrophages that engulfed a pathogen then presented its antigen on cell membrane
2. Body cells infected with virus that presents viral antigen on cell membrane
3. Transplanted cell of same species with different antigens on membrane
4. Cancer cells with unusual antigens on membrane

Question 16

What do T-Lymphocytes specifically target on a cell?

Answer 16

Antigen

Question 17

Why is T-Lymphocyte response a specific response?

Answer 17

Because each lymphocyte specifically recognises an individual pathogen

Question 18

What are Cytokines, and what are they released by?

Answer 18

• Cytokines are chemical messengers that stimulate response in all T-cells
• They are released by Helper T Cell

Question 19

Which cell in T-Cells can the B-Cell not work without?

Answer 19

The helper T cell

Question 20

What does helper T cells alert to both T and B cells?

Answer 20

The prescence of a pathogen

Question 21

What can memory cells help to do when exposed to a pathogen? [3]

Answer 21

• They can replicate themselves when exposed to an invading pathogen
• Remain in lymph nodes searching for pathogen
• Faster immune response

Question 22

How are T-Cells activated?

Answer 22

• It has receptor proteins on surface which binds to complementary antigens
• This mean T-cell is activated
• It divides and produces clones

Question 23

What happens in Cell Mediated Immunity? [4]

Answer 23

Helper T cells:

• Help B cells develop into plasma cells so they can secrete antibodies
• Help B cells develop into memory B cells
• Activate cytotoxic T cells
• Activate phagocyte

Question 24

What are B cells covered with?

Answer 24

Antibodies

Question 25

When the B cells binds to antigen by antibody, what does this form?

Answer 25

Antigen-Antibody Complex

Question 26

What happWhat do Plasma cells do?

Answer 26

They release antibodies