T3- infection and response

Question 1

what is a communicable disease

Answer 1

disease caused by a pathogen which can be passed between animals/plants

Question 2

what is a pathogen

Answer 2

a disease-causing microorganism

Question 3

how do bacteria cause disease

Answer 3

divide rapidly by binary fission
kill cells and produce harmful toxins

Question 4

how do viruses cause disease

Answer 4

invade and reproduce inside body cells
leads to cell damage

Question 5

give 3 ways in which pathogens can be spread

Answer 5

by air
by water
by direct contact

Question 6

give 4 ways in which the spread of pathogens can be reduced

Answer 6

hygiene- washing hands
reducing contact with infected individuals- quarantine
removing vectors- use of pesticides
vaccination

Question 7

what is measles

Answer 7

viral disease
symptoms-fever, red skin rash
spread- through air (inhaling sneeze droplets from infected person)

Question 8

what is HIV/AIDS

Answer 8

viral disease
attacks immune system until it can’t function properly
bodily fluid exchange /spread through sexual contact
AIDS is a result of a long-term HIV infection
no vaccine/cure

Question 9

what is TMV

Answer 9

viral disease
pathogen causes leaf discolouration when cells get damaged
affected areas can’t photosynthesise- stunted growth
no treatment
spread through contact with infected plants

Question 10

what is salmonella

Answer 10

bacterial disease
found in raw meat, poultry, unhygienic kitchens
symptoms-cramps, vomiting, diarrhea

Question 11

how to reduce spread of salmonella

Answer 11

vaccinating animals intended for consumption
disinfect surfaces after contact with raw meat
cook meat properly

Question 12

what is gonorrhoea

Answer 12

STD bacterial infection
unprotected sex with an infected person
symptoms- yellow/green discharge, pain while urinating
use antibiotics and condoms

Question 13

what is rose black spot

Answer 13

fungal disease
causes purple/black spots on leaves
affected area can’t photosynthesise
causes leaves to turn yellow and fall off
spread by fungal spores in the wind

Question 14

how to prevent rose black spot

Answer 14

fungicides
destroying infected leaves

Question 15

what is malaria

Answer 15

protist disease
carried through vectors- mosquitoes, which transfer the protist to the bloodstream
symptoms- fever, shaking , headaches, vomiting, diarrhea

Question 16

how to reduce spread of malaria

Answer 16

insecticides
insect nets- avoid bites
wear insect repellent

Question 17

how does skin act as a barrier to pathogens

Answer 17

physical barrier
scab formation after skin is cut
antimicrobial secretions kill pathogens

Question 18

how does respiratory system act as a barrier to pathogens

Answer 18

nose- has hairs and mucus to trap pathogens
trachea+bronchi- mucus to trap pathogens and cilia to move mucus to mouth to be swallowed

Question 19

how does the stomach act as a barrier to pathogens

Answer 19

chemical barrier
has hydrochloric acid to kill bacteria

Question 20

how does phagocytosis protect the body against disease

Answer 20

WBC engulf and destroy pathogens so they can’t infect more cells
-phagocyte’s membrane surrounds pathogen
-enzymes inside the cell breaks down the pathogen which destroys it

Question 21

how do antibodies protect the body against disease

Answer 21

WBC produce antibodies which are complementary to a specific antigen
this causes the pathogens to clump together, making it easier to destroy
if you become infected again the correct antibodies produce rapidly so you won’t feel symptoms

Question 22

how do antitoxins protect the body against disease

Answer 22

bind to toxins released by pathogens to neutralise them

Question 23

what is a vaccine

Answer 23

contain a dead/inactivated from of the pathogen which stimulates WBCs to produce complementary antibodies to the pathogen
if you become infected again, memory cells can rapildy produce the correct antibodies so you won’t feel symptoms

Question 24

what is herd immunity

Answer 24

immunising a large proportion of the population so the pathogen is reduced, as less people can catch it

Question 25

advantages of vaccines

Answer 25

-have eradicated many deadly diseases
-many epidemics have been prevented
-herd immunity protects those who haven’t been vaccinated

Question 26

disadvantages of vaccines

Answer 26

-not guaranteed to work
-side reactions can occur in response to the vaccine

Question 27

what drugs can cure some bacterial diseases and give example

Answer 27

antibiotics- kill pathogens inside the body
penicillin

Question 28

how do antibiotics work

Answer 28

kill bacterical pathogens inside the body but don’t kill human cells

Question 29

why can’t antibiotics be used to treat viral diseases

Answer 29

they have no effect on viral pathogens as they live inside the host’s cells, so they would kill the pathogen and the body cell

Question 30

what is antibiotic resistance

Answer 30

occurs when mutations lead to individual bacteria being resistant to an antibiotic
they can survive, reproduce and lead to a greater proportion of antibiotic-resistant bacteria

Question 31

how to prevent antibiotic resistance

Answer 31

avoid overuse and unnecessary use
finish courses to ensure all bacteria is killed

Question 32

what do painkillers do

Answer 32

reduce symptoms

Question 33

which plant is digitalis extracted from

Answer 33

foxglove

Question 34

which painkiller originated from will bark

Answer 34

aspirin

Question 35

3 qualities of a good medicine

Answer 35

effective
safe
stable

Question 36

3 factors tested when developing new drugs

Answer 36

toxicity
efficacy
dose

Question 37

how is preclinical testing carried out

Answer 37

in a lab
use cells, tissues and live animals

Question 38

how is clinical testing carried out

Answer 38

using healthy volunteers and patients
1. drug is tested as a low dose on healthy people
2. drug is tested on patients to find optimum dose
3. one group receives placebo, one receive the real drug, to assess its efficacy

Question 39

difference between single-blind trial and double-blind trial

Answer 39

single-blind: only the doctor knows if patient is receiving a placebo or drug
double-blind:neither know if its a placebo or drug. Removes bias

Question 40

how are monoclonal antibodies made

Answer 40

1. antigen injected into mouse
2. lymphocytes produced (produce specific antibodies)
3. spleen cells fuse with tumour cells
4. hybridoma cells formed
5. hybridoma divide and produce lots of mAbs
6. mAbs are collected and purified in lab

Question 41

what happens on a pregnancy test if you’re pregnant

Answer 41

HCG binds to the blue bead antibodies.
They move to the fixed antibodies and make the test strip blue