4.1 Communicable diseases

Question 1

What is clonal selection?

Answer 1

Selection of a specific B or T cell that is specific to the antigen.

Question 2

What is a neutrophil?

Answer 2

A type of white blood cell that engulfs foreign matter and traps in a large vacuole called a phagosome.

Question 3

What are opsonins?

Answer 3

Antibodies that bind to the antigen on a pathogen and then allow phagocytes to bind.

Question 4

What are secondary defences?

Answer 4

Defences used to combat pathogens that have entered the body.

Question 5

What are phagocytes?

Answer 5

The first line of secondary defence is phagocytosis where the phagocytes engulf and digest the pathogens.

Question 6

What are macrophages?

Answer 6

similar to phagocytes, except they don’t fully digest the pathogen as it moves an antigen from the surface of the pathogen and attaches it to its own special protein complex, so other immune response cells can recognise the antigen.

Question 7

How do antigen presenting cells help the lymphocytes?

Answer 7

As there may be only one Tand one B cell which is specific to the pathogen, so the chances of meeting the pathogen are small.
Therefore these antigen presenting cells may increase the chances the antigen will come in contact with them

Question 8

What do T helper cells do?

Answer 8

T helper cells release cytokines that activate specific T and B lymphocytes which would be made complimentary to the pathogens antigens.

Question 9

What are the four types of T lymphocytes?

Answer 9

• T helper cells
• T killer cells
• T memory cells
• T regulator cells

Question 10

What do T killer cells do?

Answer 10

Attack and kill cells which display foreign antigens

Question 11

What do T memory cells?

Answer 11

Provide long term immunity, as they circulate around in the blood

Question 12

What are T regulator cells?

Answer 12

They shut down the immune respone after the pathogen has been successfully removed. They are also involved in preventing autoimmunity

Question 13

What are the different types of B lymphocytes?

Answer 13

• plasma cells

- b memory cells

Question 14

What is the difference between plasma cells and b memory cells?

Answer 14

Plasma cells circulate in the blood releasing antibodies.

B memory cells remain in the body for years and help for a quicker immune response second time round.

Question 15

What do monokines do?

Answer 15

Monokines is a chemical released by macrophages that either:
-Attract or neutrophils
or
-stimulate b cells to differentiate and release anybodies.

Question 16

What are antibodies?

Answer 16

Special proteins that attach to antigens, rendering them harmless allowing a phagocyte to attach and ingest the phagocyte.

Question 17

What is the name of the region on an antibody which is specific to the shape of the antigen?

Answer 17

The Variable region

Question 18

What is the name of the region on an antibody which allows binding to our own phagocytes cells and is the same in every antibody?

Answer 18

Constant region

Question 19

What is the hinge region?

Answer 19

The region in the middle of the antibody which allows flexibility for movement, and it to bind to more than one molecule at once

Question 20

What is the role of disulfide bridge in an anti body?

Answer 20

Hold the polypeptides together.

Question 21

What is agglutination?

Answer 21

When antibodies clump together with other pathogens which:

• stops them from passing through host cell membranes
• makes them easier to be engulfed.

Question 22

What are anti-toxins?

Answer 22

Antibodies that bind to toxins released by pathogenic cells, rendering them harmless.

Question 23

What are protista?

Answer 23

Eukaryotic cells which can act as pathogens and infect cells such as the malaria protista.

Question 24

What are the stages of specific immune response?

Answer 24

1) The foreign antigen is detected
2) Phagocytosis occurs
3) Antigen-presenting cells present antigen
4) Correct T and B cells are selected
5) Correct t cells undergo clonal expansion through mitosis
6) T-helper cells release cytokines that stimulate b-cells to differentiate neutrophils
7) reproduction of B cells

Question 25

What are the functions of antibodies?

Answer 25

- Agglutinating pathogens (clumping together of pathogens and antibodies) - neutralising toxins - neutralising pathogens - opsonisation (allow phagocytic cells to bind more easily and destroy the pathogens)

Question 26

How do vaccinations work?

Answer 26

A weakened version of the pathogen is injected, which triggers immune response and memory lymphocytes to be made.

Question 27

What is herd vaccination?

Answer 27

When a vaccine is used to provide immunity to all or almost all of the population at risk. Once enough people are immune the disease can no longer be spread.

Question 28

What is ring vaccination?

Answer 28

When a new case of a disease is reported and all the people in the immediate vicinity of the disease are vaccinated. This is also often used for controlling diseases affecting live stock.

Question 29

What are the different types of immunity?

Answer 29

natural or artificial immunity and passive or active immunity

Question 30

What is the difference between natural and artificial immunity?

Answer 30

Natural immunity is achieved through normal life process such as catching chicken pox. Artificial is achieved through medical intervention.

Question 31

What is the difference between active and passive immunity?

Answer 31

Active immunity is when the immune system is activated and manufactures its own antibodies. Passive immunity is when antibodies are supplied from another source such as during pregnancy through the placenta or by injection of antibodies.

Question 32

What is the wave hub regeneration project?

Answer 32

A wave power research project. Costs - 42 million to build - potential disturbance of that area of the Cornish coast for marine life Benefits - Earn £76 million in the next 25 years for the Cornish economy - create 170 jobs - reducing the brain drain

Question 33

What was the benefits and costs of the superfast broadband regeneration project in Cornwall?

Answer 33

``` Costs -£132 million Benefits -encourages businesses to set up -aids the knowledge economy and those who work from home -hence reducing the brain drain -economic impact of £200 million ```

Question 34

Where are t-cells matured?

Answer 34

Thymus

Question 35

Where are b-cells matured?

Answer 35

Bone marrow

Question 36

Which cells release antibodies?

Answer 36

B cells | plasma and memory cells

Question 37

How can you recognise a neutrophil from other phagocytes?

Answer 37

They have a multi-lobed nucleus.

Question 38

Why do other cells of the immune system not attack macrophages when they become an antigen-presenting cell?

Answer 38

Because the antigen is displayed on a special protein complex.