disease and immunity

Question 1

what is a pathogen

Answer 1

an organism or virus that causes disease

Question 2

what is a transmissible disease

Answer 2

a disease in which the pathogen can be passed from one host to another

Question 3

pathogens way be:

Answer 3

• fungi (athletes foot)
• bacteria (streptococcus)
• protoctists (plasmodium malaria)
• viruses (HIV)

Question 4

how do pathogens get transmitted

Answer 4

A) through direct contact
B) indirect

Question 5

who do we control the spread of bacteria

Answer 5

1) hygienic food preparation
2) clean water supply
3) good personal hygiene
4) proper waste disposal
5) sewage treatment
6) vaccination

Question 6

how is cholera caused

Answer 6

by a bacterium which is transmitted in contaminated water
the bacteria releases a toxin
the toxin causes the intestine to release chloride ions in the small intestine
the water potential decreases so water enters by osmosis

Question 7

what are the symptoms of cholera

Answer 7

diarrhoea

Question 8

what is the treatment for cholera

Answer 8

rehydration therapy
antibiotic treatment

Question 9

what are our bodies mechanical barriers

Answer 9

• skin
• hair in nose (filters
• eyelashes

Question 10

what are our bodies chemical barriers

Answer 10

• mucus ->traps bacteria (produced by goblet cells in the trachea bronchi)
• hydrochloric acid in the stomach -> kills bacteria

Question 11

what cells defend our body from pathogens

Answer 11

white blood cells:
a) phagocytes -> engulf
b) lymphocytes -> produces antibodies

Question 12

how can our bodies defence be enhanced

Answer 12

by vaccination

Question 13

why do the phagocytes have an irregular nucleus

Answer 13

so they can squeeze between the cell lining of the capillaries, escape and move to the site of infection

Question 14

what happens after they engulf the pathogen

Answer 14

they digest it using enzymes

Question 15

what is active immunity

Answer 15

defence against a pathogen by antibody production in the body

Question 16

what is an antigen

Answer 16

molecule on the surface that triggers an immune system/ antibody production

Question 17

what is an antibody

Answer 17

protein produced by lymphocytes in lymph notes that recognise & binds to a specific antigen and
a) directly destroys the pathogen
b) marks it for destruction by phagocytes

Question 18

how do we get long term immunity

Answer 18

some lymphocytes remain in the lymph notes and form memory cells

Question 19

what is the order of active immunity

Answer 19

1. pathogen enters
2. lymphocytes produce antibody
3. antibody recognises antigen
4. destroys or marks
5. creation of memory cells

Question 20

how do we gain active immunity

Answer 20

after infection
by vaccination

Question 21

what is vaccination

Answer 21

introducing to the body a weakened pathogen or their antigen
antigen trigger and immune response, ie lymphocytes produce antibodies
memory cell are produced -> long term immunity

Question 22

why is vaccination important

Answer 22

protects individuals receiving the vaccine and reduces the spread of the disease

Question 23

what is a drug

Answer 23

any substance taken into the body that modifies or alters chemical reactions in the body

Question 24

what are antibiotics used to treat

Answer 24

bacteria

Question 25

how to antibiotics work

Answer 25

they disrupt production of the cell wall or protein synthesis

Question 26

why dont antibiotics affect viruses

Answer 26

because they dont have cell walls, metabolism or ribosomes to protein synthesize