B2 - The Human Immune Systum

Question 1

What is the most important part of the immune system

Answer 1

White blood cells

Question 2

What are the molecules on the surface of every cell called?

Answer 2

Antigens

Unique to each specific cell type

Question 3

How do white blood cell identify the antigens on a cell?

Answer 3

White blood cells have a special membrane which helps the to identify antigens on pathogens

Question 4

In a healthy person how do white blood cells recognise antigens on pathogens and body cells?

Answer 4

Pathogen: non-self (foreign)

Normal body cell: self

Question 5

What is the immune system triggered to do when it comes across foreign antigens?

Answer 5

Destroy invading pathogens.

Question 6

Name three ways the immune system attacks invading pathogens

Answer 6

Consume pathogens
Produce antibodies
Produce antitoxins

Question 7

What are phagocytes?

Answer 7

White blood cells with a flexible membrane that contain a lot of enzymes.

Question 8

What is Phagocytosis?

Answer 8

Some white blood cell, called phagocyte, engulfs and digests a foreign pathogen

Question 9

How are antibodies produced?

Answer 9

The White blood cell come across a foreign antigen
Receptors In the membrane bind to the antigens
The cell start to produce proteins called antibodies
The antibodies lock onto the antigens of the pathogens and bind them together.
The antibodies will only bind to that type of antigens.

Question 10

How are more antibodies produced after the initial pathogen has been detected?

Answer 10

The white blood cells that detected the pathogens will divide to produce clones so that more antibodies can be produce.
Antibodies are produced rapidly and carried around the body to lock onto similar pathogens.

Question 11

How do antibodies help phagocytes find pathogens?

Answer 11

The antibodies tag and disable the pathogens.

Question 12

What are memory cells?

Answer 12

Some white blood cells stay in the blood stream after the pathogens have been fought off.

If the same pathogens attack again the the White blood cells will trigger the memory cell to produce antibodies.

Question 13

What happens when a person is infected with a pathogen they have previously fought off?

Answer 13

The memory cell rapidly produce antibodies to prevent the spread of it.

Question 14

What are the B-lymphocytes

Answer 14

White blood cells that produce antibodies.

Question 15

Why do some white blood cells produce antitoxins?

Answer 15

To counteract toxins produced by some pathogens, limiting damage done.

Question 16

Give one role of antibodies in the immune response. (1 mark)

Answer 16

To tag and disable pathogens which helps the White blood cells (phagocyte) to find them and engulf them.

Question 17

Describe the role of the memory cell in the immune response. (2 mark)

Answer 17

Memory cells remain in the blood after the first infection of the pathogens. (1 mark)

If the same pathogen enters the body again they trigger the rapid production of antibodies so the pathogens doesn’t cause disease.