3.6

Question 1

How is the specific immune response brought about?

Answer 1

by lymphocytes that come from stem cells in the bone marrow

Question 2

What are lymphocytes?

Answer 2

white blood cells involved in the specific immune response. They aid the immune system by identifying specific antigens on pathogens.

Question 3

What is the specific immune response?

Answer 3

the response that occurs from immune cells recognising particular antigens on the pathogen surface.

the specific immune response involves T and B lymphocytes and antibodies.

Question 4

What are antigens?

Answer 4

molecules that lie on the surface of pathogens that can be detected by the immune system.

recognised by the body as non-self or foreign

Question 5

Where are B lymphocytes created from?

Answer 5

the remaining lymphocytes that mature in the bone marrow

Question 6

What is the role of B lymphocytes?

Answer 6

B lymphocytes produce antibodies in response to detecting specific antigens on the surface of a pathogen, leading to the destruction of the pathogen.

Question 7

How do antibodies aid in the immune response?

Answer 7

Many antibodies can stick to the pathogen, rendering it inactive.

Question 8

How does an allergic reaction happen?

Answer 8

B lymphocytes can trigger the immune response to a substance that is not harmful to the body, such as nuts or pollen

Question 9

Where are T lymphocytes created?

Answer 9

in the thymus

Question 10

What is the role of T lymphocytes?

Answer 10

T lymphocytes recognise specific antigens on the cell membranes of pathogens and kill these pathogens by initiating apoptosis.

Question 11

What is apoptosis?

Answer 11

programmed cell death

Question 12

How do T lymphocytes aid in the immune response?

Answer 12

T lymphocytes kill pathogens by inducing apoptosis. T lymphocytes can also stimulate other immune cells to aid in the immune response by releasing cytokines.

Question 13

What happens when T lymphocytes don’t recognise the body’s own cells?

Answer 13

When T lymphocytes don’t recognise the body’s own cells, they can respond to self-antigens. This leads to autoimmune disease, where the immune system attacks the body’s own cells.

Question 14

Describe the importance of cell memory in the immune system

Answer 14

Some B and T lymphocytes survive long-term and act as memory cells. When exposed to an antigen for the second time, these cells are familiar with the required response and rapidly divide and give rise to new and specific clone lymphocytes, made to rackle this specific antigen.

Question 15

What is HIV?
(human immunodeficiency virus)

Answer 15

a blood-borne virus that attacks the immune system by attacking and destroying T lymphocytes

Question 16

How does HIV lead to AIDS?
(acquired immunodeficiency syndrome)

Answer 16

the disease caused by HIV, where T lymphocytes have been significantly depleted, making the body very susceptible to infectious diseases.

Question 17

What is an antigen described as?

Answer 17

non-self or foreign

Question 18

How does B lymphocytes multiply to form antibodies for immediate use?

Answer 18

A B lymphocyte specific to a foreign antigen responds to the presence of the antigen by multiplying to form a clone of activated B cells.

Question 19

How does B lymphocytes multiply to form antibodies for future use?

Answer 19

A B lymphocyte specific to a foreign antigen responds to the presence of the antigen by multiplying to form a clone of memory B cells capable of making antibodies.

Question 20

How is pathogen destroyed?

Answer 20

the formation of an antigen-antibody complex inactivates the pathogen and makes it susceptible to phagocytosis

Question 21

What is an antibody?

Answer 21

a y-shaped protein molecule.

each of its arms bears a receptor binding site specfic to a particular antigen on a pathogen

Question 22

How does an allergic reaction happen?

Answer 22

it over-reacts by B lymphocytes responding to harmless substances such as pollen, dust, feather or penicilin

such hypersensitivity in the form of over exaggerated immmune response is alled an allergic reaction