Immunity

Question 1

external defence against disease

Answer 1

skin - epidermis

Question 2

internal defence against disease (3)

Answer 2

blood clotting
stomach acid
epithelial in airway barrier

Question 3

types of leucocytes

Answer 3

lymphocytes/phagocytes

Question 4

purpose of lymphocytes

Answer 4

immune response by releasing antibodies

Question 5

purpose of phagocytes

Answer 5

mark for lymphocytes or engulf

Question 6

how does the body distinguish between non-self and self

Answer 6

own cells have cell surface antigens that are detected as foreign in someone else’s body but normal in your own

Question 7

when are antibodies produced

Answer 7

when lymphocytes meet foreign antigen

Question 8

where are white blood cells made

Answer 8

bone marrow

Question 9

types of phagocytes

Answer 9

neutrophils/macrophages

Question 10

purpose of phagocytes

Answer 10

remove dead cells and breakdown of pathogen/bacteria

Question 11

process of phagocytes (6)

Answer 11

1. chemotaxis - histamine released to attract pathogen to site
2. binding by complementary shape to antibody
3. bacteria marked by antibody
4. endocytosis
5. lysosome/phagocyte vacuole breakdown
6. digestion by proteases + enzymes

Question 12

where are neutrophils found

Answer 12

blood

Question 13

how many of leucocytes are neutrophils

Answer 13

60%

Question 14

describe neutrophils

Answer 14

squeezes through capillaries
short lived and die
released in large numbers

Question 15

where are macrophages found

Answer 15

organs

Question 16

describe macrophages (4)

Answer 16

monocytes in blood that mature into macrophages in organs
larger than neutrophils
(lungs/kidney/lymph nodes)

Question 17

describe lymphocytes

Answer 17

smaller than phagocytes

large nucleus

Question 18

describe B cells

Answer 18

release antibodies and made in bone marrow where its spread through body
one mature B cells = one antigen

Question 19

describe activated B cells

Answer 19

plasma cells (short time)
memory cells (long time)

Question 20

how are B/T cells matured (3)

Answer 20

• B cells divide by mitosis to form clones
• antibody receptors produced
• mature B cells circulate in liver

Question 21

how do B cells work (4)

Answer 21

primary response: one B cell antibody spots antigen
mitosis
plasma cells secrete antibodies
secondary response: memory cells divide to form more plasma cells

Question 22

describe T cells

Answer 22

differentiate into memory cells

mature in thymus

Question 23

describe helper T cells

Answer 23

release cytokines to stimulate
B cells - plasma cells/secrete antibodies
phagocytosis

Question 24

describe killer T cells (2)

Answer 24

• search for cells with pathogen on cell surface membrane

- recognise antigens and attach to surface and secrete hydrogen peroxide (kills cells/pathogens)

Question 25

where are antibodies found during an immune response

Answer 25

surface of pathogens NOT on memory cells

Question 26

how do vaccines work (8)

Answer 26

active immunity;
vaccine contains pathogen;
immune response;
B cells secrete antibodies;
T helper cells;
clonal selection;
memory cells remain;
faster secondary response;

Question 27

describe antibodies (4)

Answer 27

• globular + glycoprotein
• specific
• hinge for flexibility
• antigen bind to variable region

Question 28

describe the structure of antibodies

Answer 28

heavy chain on the bottom and light chain on the top with disulphide bonds between chains

Question 29

describe artificial active

Answer 29

vaccination

Question 30

describe artificial passive

Answer 30

direct injection of antibodies

Question 31

describe natural active

Answer 31

your own body makes antibodies to infection

Question 32

describe natural passive

Answer 32

breast milk passing antibodies

Question 33

problems with vaccines (5)

Answer 33

• poor response
• live virus
• antigenic variation
• antigen concealment
• more than one strain

Question 34

why was small pox able to be eradicted? (5)

Answer 34

• didn’t mutate/change surface antigen
• infected people were easy to identify
• didn’t affect animals
• cheap to produce vaccines
• same vaccine used

Question 35

describe autoimmune diseases

Answer 35

immune system attacks one or more self antigens

Question 36

how do autoimmune diseases come along (3)

Answer 36

maturation of T cells in thymus gland
many cells destroyed - they are complementary to self antigens
some don’t and activate immune system to protein destruction

Question 37

describe myastenia gravis

Answer 37

affects neuromuscular junctions

antibody blocks acetylcholine receptor blocking the motor neurones

Question 38

symptom of myastenia gravis

Answer 38

muscle weakness

Question 39

where does multiple sclerosis affect

Answer 39

central nervous system

Question 40

symptom of multiple sclerosis

Answer 40

progressive paralysis

Question 41

where does rheumatoid arthritis affect

Answer 41

joint

Question 42

symptom of rheumatoid arthritis

Answer 42

progressive destruction of joints

Question 43

where does type 1 diabetes affect

Answer 43

endocrine tissue in pancreas

Question 44

symptom of type 1 diabetes

Answer 44

destruction of cells that secrete insulin

Question 45

where does systemic lupus erthromotasus affect

Answer 45

skin, kidneys and joints

Question 46

symptom of systemic lupus erthromotasus

Answer 46

progress deformity