Topic B3 Infection&Response Flashcards
What are Pathogens?
Microorganisms that enter the body and cause disease.
What kind of diseases do Pathogens cause?
Communicable (infectious) diseases.
What are communicable diseases?
Diseases that can spread.
Who is infected by pathogens?
Plants and animals.
Name the 4 main types of Pathogens:
Bacteria
Viruses
Protists
Fungi
3 ways Pathogens can be spread are:
1) Water - drinking or bathing in dirty water.
2) AIR - can be carried in the air so can be breathed in.
3) DIRECT CONTACT - by touching surfaces they’re on e.g. the skin.
4 things you can do to prevent or reduce the spread of disease:
1) BE CLEAN - wash hands before making food.2) DESTROYING VECTORS - vectors are organisms that cause disease.3) ISOLATING INFECTED PEOPLE - keep someone with a communicable disease away from you.4) VACCINATIONS
What kind of cells are bacteria?
Very small living cells.
Bacteria reproduces …..
Rapidly in your body.
Bacteria can ………….. by …….
Make you feel ill by producing toxins.
Give two examples of Bacterial diseases:
SalmonellaGonorrhoea
What is Salmonella?
A type of bacteria that causes food poisoning.
Symptoms of Salmonella:
- fever- stomach cramps- vomiting- diarrhoea
2 ways you can get Salmonella:
- eating food with salmonella bacteria in it.- eating food that has been made where the bacteria is present.
What are poultry (chickens and turkeys etc) given to control Salmonella?
Vaccinations
What is Gonorrhoea caused by?
Bacteria
What is Gonorrhoea?
A sexually transmitted disease - STD.
What causes STD’s?
Sexual contact e.g. unprotected sex.
2 symptoms of Gonnorhoea:
- pain when urinating.- thick yellow or green fluid from the genitals.
How did Gonnorhoea used to be treated and why has it changed?
Penicillin. New types of Gonnorhoea are resistant to penicillin so it doesn’t work.
2 ways to prevent Gonorrhoea:
- get treated with other antibiotics.- use condoms.
Are Viruses cells?
No, they are much smaller.
Where do Viruses live?
Inside your cells.
What do Viruses do in your body?
Reproduce rapidly.
What happens to a cell with viruses are reproducing inside it? Then?
It will usually burst releasing all the new viruses.The cell damage makes you feel ill.
What kind of disease is Measles?
A viral disease.
How is measles spread?
By droplets from an infected person’s sneeze or cough.
Symptoms of measles:
Red skin rashFever
People can die from measles if there are c……Give 2 examples:
Complications (problems).Can sometimes lead to pneumonia (a lung infection) or a brain infection called encephalitis.
When are people vaccinated against measles?
When they are young.
What is HIV?
A virus.
What spreads HIV?
Sexual contactExchanging body fluids e.g. Blood.
Symptoms of HIV and when they occur?
Flu like symptoms for weeks then no symptoms for 8 years.
With what can HIV be controlled? How?
Antiretroviral drugs. They stop the virus copying itself in the body.
What happens if the HIV cells aren’t controlled?
The virus attacks the immune cells.
What happens if HIV badly damaged the body’s immune system?
It can’t cope with other infections or cancers.
What is the last stage of HIV known as?
AIDS.
What is Tobacco Mosaic Virus?
A virus that affects many species of plants e.g. Tomatoes.
What does Tobacco Mosaic Virus do?
It causes parts of the leaves to be discoloured giving it a mosaic pattern.
What happens to the discoloured leaves caused by Tobacco Mosaic Virus?
The leaves have less chlorophyll to absorb light = less photosynthesis so the plant can’t make enough food.
What is Rose Black Spot?
A disease caused by a fungus.
What does the fungus in Rose Black Spot cause?
Purple or black spots on the leaves of rose plants then they turn yellow and fall off.
What happens when the leaves drop of because of Rose Black Spot?
Less photosynthesis = the plant doesn’t grow very well.
How is Rose Black Spot spread?
By the water or by the wind.
How can gardeners treat Rose Black Spot?
Fungicides - chemicals that kill fungi.Stripping the affected leaves then destroying them so the fungus can’t spread.
What is Malaria?
A disease caused by a protist.
Where does part of a protist’s life cycle take place?
Inside a mosquito. The mosquitos are now vectors.
4 steps to a mosquito spreading Malaria:
- the mosquitos pick up the protist when they feed on an infected animal.
- they don’t get malaria.
- they pass it on to animals when they bite them.
- animals get malaria
What does Malaria cause:
Repeating episodes of fever.Death.
How can the spread of malaria be reduced?
By stopping mosquitos from breeding.
How can people be protected from mosquito bites?
Mosquito nets.
What does your skin do to protect you?
Stops pathogens getting inside and releases substances that kill them.
How do nose hairs protect you?
They trap particles that could contain pathogens.
How does mucus (snot) protect you?
The tranchea and bronchi release mucus to trap pathogens.
How does Cilia ( hair like structures) protect you?
The tranchea and bronchi are lined with this. They move the mucus to the back of the throat where it can be swallowed.
How does your stomach acid protect you?
The hydrochloric acid kills pathogens in the stomach.
What happens if pathogens do make it into your body?
Your immune system kicks in to destroy them.
Most important part of your immune system?
The white blood cells.
3 lines of a white blood cells attack:
1) PHA-GOCY-TOSISThey surround the pathogens and digest them.
2) PRODUCING ANTIBODIES Every invading pathogen has unique molecules. If there are foreign antigens (molecules) the antibodies lock onto it so the white blood cells can trap it.
3) PRODUCING ANTI TOXINS they stop toxins produced by the invading bacteria from working.
What do Vaccinations do?
They protect you from future infections
What do vaccinations involve? What is the outcome?
Objecting small amounts of dead pathogens with antigens on the surface. Your antibodies attack it. Then if you get infected with it later your body can fight it already.
PRO’S OF VACCINES:
They helped to control lots of diseases that used to be common e.g. Polio.
There are fewer people to pass the disease on if everyone is vaccinated.
What is a epidemic?
A big outbreak of a disease.
How can epidemics be prevented?
If lots of people are vaccinated.
CONS OF VACCINES:
They don’t always work and sometimes don’t give you immunity.
You can sometimes have a bad reaction to a vaccine e.g. Swelling or a fever.
Some drugs helps to get rid of the symptoms of a disease. Give an example of this.
Painkillers reduce pain.
Antibiotics kill bacteria. Give an example of an antibiotic that kills bacteria.
Penicillin
Why can’t antibiotics destroy viruses?
Because viruses reproduce using your own body cells. So it is difficult to get drugs that destroy the virus without killing the body’s cells.
How can bacteria become resistant to antibiotics?
Bacteria can change and some of the changes may cause the bacteria to become resistant to the antibiotic meaning that the anti biotics will only kill the non resistant and the ones left will survive and reproduce. (example of natural selection)
Why have resistant types of bacteria increased?
Because of natural selection.
Why do our drugs come from plants?
Plants produce chemicals to defend themselves against pests and pathogens.
What is ASPIRIN the pain killer made from?
A chemical found in willow.
What is DIGITALIS which is used to treat heart conditions made from?
A chemical found in foxgloves.
Give an example of a drug that comes from microorganisms:
ALEXANDER FLEMING found that a type of mould - Penecillium makes a substance that kills bacteria. THIS IS PENICILLIN.
Where are new drugs made?
Pharmaceutical industry ( companies that make and sell drugs )
Who are drugs made by?
Chemists in labs.
2 different stages in the development of new drugs:
Preclinical testingClinical testing
What are drugs first tested on in preclinical testing?
Human cells and tissues in the lab.
In preclinical testing the second step is testing the drug on live animals. Why?
To find out:
1) it’s efficacy (If it works)
2) it’s toxicity ( harmful? side effects?)
3) it’s dosage ( the concentration that works best and how often it should be taken)
What happens in clinical testing?What happens if there are good results?
Drug tested on healthy volunteers to make sure there are no harmful side effects. Dosage increased little by little. GOOD RESULTS? Tested on patients. Optimum dose is found.
What is the optimum dose?
The dose of drug that is most effective and has few side effects.
What happens after the optimum dose of a drug is found?
Patients are in two groups.
G1 - get drug
G2 - a placebo (fake drug)DOCTOR COMPARES TO SEE IF WORKS.No one knows who gets what.
Why aren’t results of drug tests published until they’ve been through peer review?
To prevent false claims.
How can doctors slow down the rate of development of resistant strains?
It’s important for doctors to avoid over prescribing antibiotics and it is also important that you finish the whole course of anti biotics.
Physically, how do plants defend them self against the invasion of microorganisms? (3)
- they have a tough waxy cuticle on leaves
- layers of dead cells around stems which may fall off
- strong cell walls made of cellulose
Chemically, how do plants defend themselves against the invasion of microorganisms? (2)
- antibacterial chemicals
- poisons to deter herbivores
Mechanically, how do plants defend themselves against the invasion of microorganisms? (3)
- mimicry to trick animals (looking like other poisonous plants)
- thorns and hairs to deter animals
- leaves which droop or curl when touched
