5: Cell Recognition and The Immune System

Question 1

Pathogen

Answer 1

Any microorganism that causes disease

Question 2

Immunity

Answer 2

The means by which the body protects itself from infection

Question 3

Phagocyte

Answer 3

White blood cells that engulf microorganisms

Question 4

Phagosome

Answer 4

The vessel that forms when the phagocyte engulfs a pathogen.

Question 5

Lysozymes

Answer 5

Hydrolytic enzymes that destroy ingested bacteria by hydrolysis of their cell wall.

Question 6

Antigen

Answer 6

Any part of an organism that is recognised as foreign and stimulates an immune response

Question 7

B-lymphocytes

Answer 7

White blood cells that are associated with humoral immunity

Question 8

T-lymphocytes

Answer 8

White blood cells that are associated with cell-mediated immunity

Question 9

Antigen-presenting cells

Answer 9

Cells that display foreign antigens in their surface

Question 10

Cell-mediated immunity

Answer 10

When T-lymphocytes respond to antigens that are presented on a body cell

Question 11

Cytotoxic T-cells

Answer 11

They kill abnormal cells and body cells that are infected by pathogens, by producing perforin that produces holes in the cell-surface membrane

Question 12

Humoral Immunity

Answer 12

Immunity that involves antibodies

Question 13

Clonal selection

Answer 13

When T-helper cells stimulate B cells to divide by mitosis to form clone identical B cells

Question 14

Plasma cells

Answer 14

Cells that secrete specific antibodies that lead to the destruction of specific pathogen

Question 15

Memory cells

Answer 15

Cloned B cells that circulate within the blood, ready for any future infection from the same pathogen

Question 16

Antibodies

Answer 16

Proteins with specific binding sites synthesised by B cells

Question 17

Antigen-antibody complex

Answer 17

This forms because each antibody has a specific binding site that fits precisely onto the specific antigen

Question 18

Variable region

Answer 18

The binding site of an antibody which is different for different antibodies

Question 19

Constant region

Answer 19

The part of the antibody that is not variable

Question 20

Monoclonal antibodies

Answer 20

A single type of antibody which is isolated and cloned outside of the body

Question 21

Antibiotic

Answer 21

A substance produced by living organisms that can destroy or inhibit the growth of bacteria

Question 22

Antibiotic resistance

Answer 22

The development in microorganism of mechanisms that prevent antibiotics from killing them

Question 23

Herd immunity

Answer 23

When a sufficiently large proportion of the population has been vaccinated to make it difficult for the pathogen to spread within the population

Question 24

Antigenic variability

Answer 24

When a pathogen mutates frequently, so that vaccines suddenly become ineffective

Question 25

Vaccination

Answer 25

The introduction of a vaccine containing appropriate disease antigens into the body

Question 26

Retroviruses

Answer 26

The group of viruses that HIV belongs to

Question 27

ELIZA test (Enzyme Linked ImmunoSorbant Assay)

Answer 27

A test used to detect HIV and other diseases, allergens and drugs