TOPIC 3 INFECTION AND RESPONSE

Question 1

what is a pathogen

Answer 1

microorganisms that enter the body and cause communicable diseases
-BOTH plants and animals can be infected

Question 2

how does bacteria make us feel ill

Answer 2

-small cells that produce toxins that damage your cells and tissues

Question 3

what makes us feel ill in viruses

Answer 3

-they live inside cells and replicate using cell machinery to produce many copies of themselves
-the cells burst which releases new viruses

Question 4

state 3 ways pathogens are spread

Answer 4

1. contaminated water, (drinking dirty water)
2. air (pathogens can be carried in air and breathed in)
3. direct contact (by touching contaminated surfaces e.g skin)

Question 5

explain the viral disease measles

Answer 5

-spread by droplets from an infected persons sneeze or cough
-affect a red skin rash and fever
-leads to pneumonia
-prevent, vaccinated when young

Question 6

HIV virus

Answer 6

-spread by sexual contact or exchanging bodily fluids
-affect flu-like symptoms
-attacks immune cells
-controlled by antiretrovial drugs

Question 7

what is the disease TMV

Answer 7

-tobacco mosaic virus
-affects many species of plants
-cause a mosaic pattern on leaves (discoloured)
-**effect **plant cannot carry out photosynthesis

Question 8

state a fungal disease

Answer 8

rose black spot
-causes purple or black spots to develop on leaves and the leaves turn yellow and drop off
-spreads through environment in water or by wind
-**treat **by stripping the plant of its affected leaves

Question 9

state a disease caused by a protist

Answer 9

malaria
-mosquitos are vectors that pick up malarial protst when they feed on infected animal
-every time the mosquito feeds on another animal it infects it
causes repeated fevers
-reduce spread by mosquito nets or stopping them from breeding

Question 10

state 2 bacterial diseases

Answer 10

-salmonella
-gonorrhoea

Question 11

what is salmonella

Answer 11

-a type of bacteria that causes food poisoning
-causes fever, stomach cramps, vomitting
-get it by eating contaminated food
-most poultry in UK is given a vaccination against this

Question 12

what is gonorrhoea

Answer 12

-sexually transmitted disease (STD)
-**transmitted by sexual contact
-symptom pain when urinating, yellow discharge from the vagina
-treated by **antibiotics
-use condoms to stop spread

Question 13

4ways to reduce disease

Answer 13

1. be hygenic, wash hands with soap thoroughly
2. destroy vectors
3. isolate infected individuals
4. vaccinations

Question 14

how does the skin act as a defence system

Answer 14

-acts as a barrier to pathogens

Question 15

how does your nose act as a defence system

Answer 15

-hair and mucus trap particles that contain pathogens

Question 16

how does the trachea and bronochi act as a defence system

Answer 16

they secrete mucus to trap pathogens
-lined with cilia

Question 17

how does the stomach act as a defence system

Answer 17

-produces hydrochloric acid

Question 18

what does the immune system do if pathogens enter the body

Answer 18

-kicks in to destory them
-the white blood cells travel around and when coming across an invading microbe they
* consume them
* produce antibodies
* produce antitoxins

Question 19

describe the 1st process of white blood cells

Answer 19

-engulf cells and digest them
-called phagocytosis

Question 20

describe the 2nd process of white blood cells

Answer 20

-invading pathogens have antigens on its surface
-start to produce proteins called antibodies
-antiboides are produced rapidly
-if the person ifnected with the same pathogen again, the persons naturally immune to that pathogen

Question 21

3rd process of white blood cells

Answer 21

-produces antitoxins
-counteract toxins produced by invading bacteria

Question 22

how do vaccinations protect from future infections

Answer 22

-inject small amounts of dead or inactive pathogens that carry antigens

Question 23

PROS of infections

Answer 23

-they control many communicable diseases that were common
-outbreaks of diseases can be prevented if a large percentage of the population is vaccinated

Question 24

CONS of infection

Answer 24

-dont always work
-can causes bad reactions, e.g swelling or fever

Question 25

state what relieves symptoms

Answer 25

-painkillers

Question 26

how do antibiotics help

Answer 26

they kill bacteria but dont destory viruses

Question 27

3main stages of drug testing

Answer 27

1. preclincal testing, drugs are tested on human cells and tissues in the lab
2. test drug on live animals
   - tests for efficacy
   - tests toxicity
   - LAW must be tested on 2different live mammals
3. if passes them tests its treated on human volunteers in a clincial trial
   -then tested on people suffering from the illness