Topic 3 (Infection and Response)

Question 1

What are pathogens

Answer 1

Microorganisms that enter the body to cause disease

Question 2

What is bacteria

Answer 2

Bacteria are very small living cells that make you feel I’ll by producing toxins that damage your cells

Question 3

What are viruses

Answer 3

Viruses are extremely small about 1/100th the size of a bacterium. They make you feel I’ll by reproducing in your cells causing them to burst.

Question 4

What are protists

Answer 4

Protists are single cell eukaryotes. They live in or on other organisms and can cause them damage

Question 5

What is fungi

Answer 5

Fungi are made ip of hyphae (Thread like structures) which can grow on human skin and the surface of plants causing diseases

Question 6

What are three ways pathogens can be spread

Answer 6

•Air
•Water
•Direct contact

Question 7

What is measles

Answer 7

Measles is a viral disease spread by droplets. It cause a red skin rash. It can be very serious and in some cases lead to pneumonia or inflammation of the brain

Question 8

What is HIV

Answer 8

HIV is a viral seaward spread by sexual contact or exchanging of bodily fluids. It initially has flu like symptoms. The virus attacks the immune system, if the immune system is badly damage it can’t cope with other infections or cancer. This is known as late stage HIV or AIDS

Question 9

What is tobacco mosaic virus

Answer 9

TMV is a viral disease that affects many species of plants. It causes a mosaic pattern on the leaves of plants. The discolouration means the plant can’t carry out photosynthesis

Question 10

What is rose black spot

Answer 10

Rose black spot is a fungal disease, it cause black or purple spots to develop on the leaves of rose plants. The leaves turn yellow and drop off, this means less photosynthesis and the plant can’t grow very well

Question 11

What is malaria

Answer 11

Malaria is a disease caused by a protist. The mosquitoes are vectors, they pick up the malarial protist when they feed on an infected animal, every time it feeds another animal it infects it. Malaria causes repeating episodes of fever which can be fatal.

Question 12

What is salmonella

Answer 12

Salmonella is a type of bacteria that causes food poisoning, infected people can suffer from fever, stomach cramps, vomiting and diarrhoea. These symptoms caused by the toxins that the bacteria releases

Question 13

What is gonorrhoea

Answer 13

Gonorrhoea is a STD passed on by sexual contact. It is caused by bacteria. An infected person will get pain when they urinate. Another symptom is thick yellow or green discharge.

Question 14

How can you prevent diseases

Answer 14

•Being Hygienic
•Destroying Vectors
•Isolating infected individuals
•Vaccination

Question 15

How does your immune system attack pathogens

Answer 15

•Phagocytosis
•Producing Antibodies
•Producing antitoxins

Question 16

How does vaccination work

Answer 16

•When you’re infected with a new pathogen, it takes your WBC’s a while to start producing antibodies but by that time you already feel pretty ill
•Vaccinations involve injecting a small amount of dead or inactive pathogens. These carry foreign antigens which causes your body to produce antibodies to destroy them even though they are harmless
•However if the live pathogen of the same type ever appears the WBC’s can rapidly mass produce antibodies as they already dealt with the pathogen before

Question 17

Positives of vaccination

Answer 17

•Help control a lot of of communicable diseases e.g whooping cough and rubella
•Big outbreaks of disease can be prevented if a large percentage of people are vaccinated (Herd Immunity)

Question 18

Negatives of vaccination

Answer 18

•Don’t always give you immunity
•Sometimes vaccines give bad reactions e.g swelling

Question 19

What do painkillers do

Answer 19

They only relieve the pain you are feeling, they don’t actually tackle the cause of the disease or kill pathogens

Question 20

What do antibiotics do

Answer 20

Antibiotic kill or prevent the growth of bacteria without killing your own body cells. However antibiotics don’t kill viruses as there is no way for them to do so without harming your body cells

Question 21

How can bacteria become resistant against antibiotics

Answer 21

•When on an antibiotic course, patients may feel better days before the course is up however not all the bacteria may be dead
•If a patient stops taking antibiotics early, bacteria remaining becomes resistant to them. The resistant bacteria reproduce creating more and more resistant bacteria which then causes the patient to feel Ill again.
•The problem is this time the antibiotics will not work as the whole population of bacteria is resistant
•This is why doctors have to be very careful when prescribing antibiotics

Question 22

Willow Bark makes

Answer 22

Aspirin

Question 23

Foxgloves make

Answer 23

Digitalis, medicine used to treat heart conditions

Question 24

Bread mould makes

Answer 24

Penicillin

Question 25

What are the three main stages of drug testing

Answer 25

•Human cells and tissues (Preclinical)
•Live animals (Preclinical)
•Human volunteers (Clinical)

Question 26

What does testing on live animals in the preclinical trials do

Answer 26

It tests the drugs efficacy (Whether it works) to find out about its toxicity and what the best dosage is.

Question 27

How do drug developers undergo clinical trials

Answer 27

•Healthy volunteers are given a small dosage to check for any harmful side effects
•The drug can then be tested on people with the illness to find optimum dosage
•This is done using double blind trials with a placebo drug, where neither doctor nor patient knows what drug is the real one and what drug is the placebo to endure the drug is truly making them feel better and it isn’t just psychological

Question 28

What are monoclonal antibodies

Answer 28

Mass produced identical antibodies

Question 29

How are monoclonal antibodies produced

Answer 29

•Antibodies are produced by lymphocytes
•Monoclonal antibodies are made from lots of clones of a single white blood cell
•However lymphocytes don’t divide very easily
•Tumour cells divide extremely easily but don’t produce antibodies
•The two cells are fused together to create a hybridoma cell which can produce antibodies and divide extremely easily.
•The antibodies produced are collected and purified. They can bind to anything you want which means they can target specific cells

Question 30

What are monoclonal antibodies used for

Answer 30

•Pregnancy tests
•Treating disease
•Research to find specific substances as you can bind due to them