immune system

Question 1

primary immune response

Answer 1

• immune system recognises foreign antigens on pathogen
• WBCs reproduce
• some of these cell become memory cells
• the rest produce antibodies which are specific to the antigen present
• antibody binds to antigen on pathogen
• they interact, leading directly to the destruction of the pathogen/engulfing of pathogen by phagocyte

Question 2

secondary immune response

Answer 2

• if an individual comes into contact with a pathogen with the same antigen again, the memory cells rapidly lead to the production of huge numbers of antibody
• the high level of antibodies tend to destroy the pathogen before the symptoms of the disease occur
• the individual is now described as ‘immune’.

Question 3

innate immune response

Answer 3

• first line of defence against pathogens
• non-specific, immediate
• function: to immediately prevent the spread and movement of foreign pathogens throughout the body
• examples: skin, hair, cough, mucous membranes, phagocytes

Question 4

adaptive immune response

Answer 4

• second line of defence against pathogens
• specific to the pathogen present
• rapid increase of T and B lymphocytes which have specific antigen receptors to fight the pathogen
• examples: pus, swelling, redness, pain,
• long lasting response (>96 hours)
• can make errors and attack itself ->autoimmune disease

Question 5

WBCs

Answer 5

• also called leukocytes

types: phagocytes and lymphocytes

Question 6

lymphocytes

Answer 6

• help the body to remember previous invaders and recognise them if they attack again
• they live in bone marrow, some stay there and develop into B lymphocytes (B cells), others head to the thymus and become T lymphocytes (T cells)
• B cells produce antibodies and help alert the T cells
• T cells destroy compromised cells in the body and help alert other leukocytes

Question 7

antigen

Answer 7

• short for antibody generator
• any substance that can spark an immune response
• e.g. a bacterium, fungus, virus, toxin, or foreign body

Question 8

antibodies

Answer 8

-Y-shaped proteins that lock on to specific antigens

Question 9

plasma B cells

Answer 9

• B lymphocytes differentiate into plasma B cells which produce antibodies
• (there is no such thing as a plasma T cell)

Question 10

where are B lymphocytes produced?

Answer 10

spleen and bone marrow

Question 11

monoclonal antibodies

Answer 11

• antibodies produced from cloned plasma B cells
• binds to only one substance
• can be used alone or to carry drugs/toxins/ radioactive substances directly to cancer cells

Question 12

ELISA technique

Answer 12

1. First antibody binds to antigen
2. Second antibody with reporter enzyme attached is added and attaches to antigen
3. Solution added and colour changes