infection and response

Question 1

how do nostrils prevent pathogens entering them?

Answer 1

with their nose hairs, sticky mucus and cilia

Question 2

how does the respiratory system prevent pathogens entering the body?

Answer 2

lined with mucus, cilia move the mucus upwards to be removed.

Question 3

how does the stomach stop pathogens from entering the body?

Answer 3

stomach acid kills most of it

Question 4

what happens when some pathogens make it into the body?

Answer 4

the immune system tries to kill them

Question 5

what are white blood cells?

Answer 5

the cells that fight off pathogens.

Question 6

how do white blood cells know the difference between proteins and pathogens?

Answer 6

because they have a different surface

Question 7

what are surface proteins called

Answer 7

antigens

Question 8

what can white blood cells do to speed up reaction time?

Answer 8

they remember what antibody they had to make the last time they had to fight off the pathogen and make it more quickly.

Question 9

what does a vaccine contain?

Answer 9

vaccines contain a small amount of dead or inactive form of the pathogen that can be introduced to the body.

Question 10

can all bacterial infections use the same antibiotic

Answer 10

no

Question 11

can antibiotics be used to treat viral infections?

Answer 11

no

Question 12

what happens when bacteria mutates?

Answer 12

it can become resistant to antibiotics and new strains have to be formed.

Question 13

digitalis is a drug for heart conditions…

Answer 13

it originates from foxgloves

Question 14

aspirin is a drug used as a painkiller…

Answer 14

it originates from willow tree bark

Question 15

penicillin is an antibiotic drug…

Answer 15

it originates from mould

Question 16

what is meant by the following terms?

• efficacy
• toxicity
• optimum dose

Answer 16

• how effective the drug is
• how poisonous the drug is
• minimum amount of the drug that provides the best response

Question 17

steps taken before a drug is released to the public…

Answer 17

1. drugs are trialled in labs on cells and tissue cultures
2. drugs are trialled on live animals.
3. drugs are trialled on healthy volunteers.
4. drugs are trialled on live animals.

Question 18

what is a placebo?

Answer 18

a medicine that does not contain the drug that is being trialled

Question 19

why are placebos used?

Answer 19

a placebo is used to check that there are no other factors which may cause the patients condition to improve without the drug

Question 20

put these statements in order to show how monoclonal antibodies are produced.

• mouse lymphocytes produce antibodies
• the antibodies are collected and purified
• mouse lymphocytes are collected
• mouse is injected with pathogen
• hybridoma cells are separated and cultured to form a clone
• mouse lymphocyte and mouse tumour cell are fused
• the clone produces large quantities of antibody

Answer 20

• mouse is injected with pathogen
• mouse lymphocytes produce antibodies
• mouse lymphocytes are collected
• mouse lymphocyte and mouse tumour cell are fused
• hybridoma cells are separated and cultured to form a clone
• the clone produces large quantities of antibody
• the antibodies are collected and purified

Question 21

what are the applications of monoclonal antibodies

Answer 21

• pregnancy testing
• used to measure levels of hormones and other chemicals in blood
• treat some cancers by delivering a toxic drug to cancer cells
• to find various molecules in cells or tissues by binding to them with a fluorescent dye

Question 22

why do some people feel the use of monoclonal antibodies is unethical?

Answer 22

• mouse has to suffer the disease deliberately
• mouse is induced to have cancer
• treatments not always safe
• it’s very expensive and money could be better used

Question 23

name 3 ways you can tell a plant is diseased?

Answer 23

-leaf spots/discolouration
-malformed stems or leaves
presence of pests
-stunted growth
-areas of decay

Question 24

ways a plant stops animals eating it mechanically?

Answer 24

to stop herbivores eating it, they grow thorns or hairs

Question 25

ways a plant stops animals eating it chemically?

Answer 25

to fight off pathogens/bacteria/herbivores/animals the plant releases antibacterial or poisonous chemicals

Question 26

ways a plant stops animals eating it physically?

Answer 26

to defend itself from herbivore and pathogen entry dead bark coating falls off

Question 27

ways a plant stops animals eating it physically?

Answer 27

waxy cuticle/cellulose cell walls are hard to penetrate

Question 28

why are nitrate ions very important for plants?

Answer 28

Nitrate is crucial for protein synthesis and hence growth. without sufficient nitrate ions, the plant would be stunted

Question 29

what is chlorosis and how can it be prevented?

Answer 29

the yellowing of leaves. it can be prevented by getting the plant magnesium

Question 30

why would a test kit containing monoclonal antibodies be useful to detect plant disease?

Answer 30

the monoclonal antibodies can be used to detect a particular chemical which is only present in one type of pathogen. this would then show whether the plant was infected or not