Ch5 Cell recognition and the immune system

Question 1

5.1 What is immunity?

Answer 1

The ability of organisms to resist infection

Question 2

5.1 How do non-specific responses differ from specific responses?

Answer 2

Non-specific responses are faster, the same for all pathogens and do not confer immunity

Question 3

5.1 What are the specific defences against pathogens?

Answer 3

Cell-mediated and humoral responses

Question 4

5.1 What type of white blood cell is involved in the non-specific response?

Answer 4

Phagocyte

Question 5

5.1 What type of white blood cell is involved in the cell-mediated response?

Answer 5

T-lymphocyte

Question 6

5.1 What type of white blood cell is involved in the humoral response?

Answer 6

B-Lymphocytes

Question 7

5.1 What potentially harmful cells/molecules does the immune system identify as non-self?

Answer 7

Pathogens, transplanted cells, toxins, cancer cells

Question 8

5.1 What is clonal selection?

Answer 8

The lymphocyte with complementary proteins to those of the pathogen divide

Question 9

5.1 How do lymphocytes distinguish between self and non-self?

Answer 9

Antigens- proteins on the surface of cells

Question 10

5.1 Where do lymphocytes ‘learn’ self from non-self?

Answer 10

Protein on the surface of cells

Question 11

5.1 What happens to lymphocytes that show an immune response to self cells in the fetus/bone marrow?

Answer 11

Lymphocytes undergo apoptosis

Question 12

5.1 What is apoptosis?

Answer 12

Programmed cell death

Question 13

5.2 What is Phagocytosis?

Answer 13

When Phagocyte engulf and destroy pathogens

Question 14

5.2 How does a phagocyte locate a pathogen?

Answer 14

It moves along a concentration gradient of chemicals produced by the pathogen

Question 15

5.2 How does a phagocyte recognise a pathogen?

Answer 15

Receptors attach to chemicals on surface of pathogen

Question 16

5.2 What is a Phagosome?

Answer 16

The vesicle formed when a pathogen is engulfed by a phagocyte

Question 17

5.2 What enzymes hydrolyse a pathogen?

Answer 17

Lysozymes

Question 18

5.2 What happens to the soluble products of hydrolysis after phagocytosis?

Answer 18

Absorbed into cytoplasm, some presented on surface of phagocyte

Question 19

5.3 What is an antigen?

Answer 19

A protein recognised as non-self that stimulates an immune response

Question 20

5.3 Where do B-lymphocytes mature?

Answer 20

Bone marrow

Question 21

5.3 Where do T-lymphocytes mature?

Answer 21

Thymus gland

Question 22

5.3 What four types of cell do T-lymphocytes respond to?

Answer 22

Phagocytes that have engulfed a pathogen, virus infected body cells, transplanted cells, cancer cells

Question 23

5.3 What term is used to describe cells that display foreign antigen on their surface?

Answer 23

Antigen presenting cells

Question 24

5.3 How is a helper T cell activated?

Answer 24

Helper T cell receptor binds to complementary antigen on antigen presenting cell