Unit 4.3 Communicable diseases Flashcards
Why do scientists peer review each others work?
To rigorously check each others work.
This makes results more valid.
Helps to prevent false claims.
Why are drugs first tested on healthy volunteers during clinical trials?
To check that the drug is safe
Give examples of diseases caused by protists (parasites).
Malaria
Giardia
Lung Worm
Who discovered penicillin?
Alexander Fleming
Do antibiotics kill pathogens? Which type?
Yes
ONLY bacteria
Explain how overuse of antibiotics can lead to antibiotic resistance in a population of bacteria.
Random Mutations cause Variation in a population of bacteria e.g. some are antibiotic resistant.
Antibiotic resistant bateria have an Advantage
Those bacteria Survive and Reproduce and pass on Genes.
Future generations will be antibiotic resistant.
(Red Monkeys Viciously Attack Smelly Red Gorrilas)
Give examples of viral diseases.
Measles
Mumps
Rubella
Influenza
Ebola
Polio
How is measles spread?
Droplets - coughs/sneezes.
If the body is infected by pathgoens _________ will react.
white blood cells
Give examples of human diseases caused by fungi.
Athlete’s foot
Thrush
Why do vaccines only protect against one specific pathogen?
Antibodies are specific
True or false - bacteria are the same size as animal cells.
False - they are about 100 times smaller.
What is herd immunity and how does it work?
Where 95% of the population is vaccinated against a disease.
This prevents disease spreading as fewer people are able to pass it on.
What is the vector for the protist that causes malaria in humans?
Mosquitoes
What are the complications of measles?
Pneumonia (chest infection)
Encephalitis (brain infection)
How do bacteria make us feel unwell?
- They produce toxins.
- They damage cells.
- They reproduce rapidly.
How does salmonella spread?
Contaminated food (undercooked chicken/eggs)
What is the body’s first line of defence against pathogen infection? (CHASM)
Cilia - waft pathogen out of lungs
Hairs - in nose trap pathogens
Acid - in stomach kills pathogens
Skin - acts as a barrier
Mucus - in lungs traps pathogens
How can we reduce the spread of disease?
- Be hygeinic
- Destroy vectors
- Isolate infected individuals.
- Vaccinate people.
Give examples of bacterial diseases
Tonsilitis
Plague
Tuberculosis (TB)
Salmonella
How can rose black spot be treated?
Use of fungicides.
Remove and destroy infected leaves.
How was penicillin discovered?
Alexander Fleming noticed a clear zone around fungi that was growing on an agar plate that he was using to grow bacteria on.
What type of pathogen causes rose black spot?
Fungus
Late stage HIV is called…
AIDs
What are the symptoms of salmonella?
Fever
Stomach cramps
Vomitting
Diarrhoea
Gonorrhoea is caused by which type of pathogen?
Bacteria.
How do fungi cause disease?
They produce thread-like hyphae.
Hyphae grow and penetrate skin/plant tissues causing disease.
Hyphae produce spores which can spread to other plants.
Identify the 3 stages of drug testing
- Human cell and tissue testing (pre-clinical)
- Animal testing (pre-clinical)
- Clinical trials (human testing)
How do viruses make us feel unwell?
- They replicate rapidly inside cells (take over cellular machinary)
- They eventually burst out of cells damaging them.
- Sometimes they produce toxins.
Do painkillers kill pathogens?
No they just relieve symptoms until the immune system kills them
What are the symptoms of malaria?
Repeated bouts of fever
Death
Why are drugs tested on human volunteers?
To check for side effects
To check for optimum dosage
To check efficacy (does it work)
What is a communicable disease?
A disease that can easily spread.
Some protists can be referred to as p________
parasites.
Are viruses cells?
No - they are non-living particles with a regular shape.
Why do we test drugs on live animals?
To check for toxicity
To check efficacy (does the drug work)
To identify the optimum dosage
What sort of drug cannot be tested on human cells and tissues?
Drugs that affect body systems e.g. blood pressure drugs require a full circulatory system not just cells so must be tested on animals.
Malaria is caused by a protist called…
Plasmodium falciparum
How can diseases spread?
Droplets
Animals
Food
Touch
(DAFT)
+ dirty water.
What are the symptoms of rose black spot?
Pruple/black spots on leaves.
Leaves can turn yellow and drop off.
Less photosynthesis.
Less growth.
True or false - only animals are infected by pathogens.
False - plants can be too.
How can we prevent malaria spreading?
Kill the vector - mosquito insecticide.
Stop mosquitoes breeding.
Anti-malarial medication.
Moquito nets
Identify the 4 groups of pathogens.
Virus
Bacteria
Fungi
Protists
How is HIV (virus) spread?
Touch - unprotected sexual contact
Exchanging bodily fluids such as blood e.g. sharing needles.
Why do antibiotics not kill viruses?
Viruses live inside cells.
Cells would have to be damaged ot destroy the virus.
What is a eukaryotic cell?
A cell whose genetic material is stored in a nucleus.
A cell containing membrane bound organelles e.g. mitochondria.
Explain how immunisation (vaccination) leads to protection against pathogens.
Injection of dead/weak pathogen.
White blood cells identify foreign antigens
White blood cells produce antibodies
Antibodies kill pathogen
If reinfeciton occurs white blood cells remember how to rapidly produce antibodies.
The unique proteins on the surface of all pathogens are called…
antigens
What is a pathogen?
A microorganism that causes infectious disease.
Describe the features of a parasite
They live on or inside organisms.
They take nutrients from their host.
They cause damage to their host.
They are often transferred to their host via a vector, which does not get the disease itself.
How can gonorrhoea be treated?
Antibiotics.
What are the early symptoms of HIV?
Flu like symptoms but then the person does not experience symptoms for years.
Eventually the immune system is damaged.
Tobocca Mosaic Virus (TMV) cause what symptoms?
Discoloroued ‘mosaic’ pattern on leaves.
Discolouraiton means less photosynthesis.
Less photosynthesis means less growth.
Digitalis is a drug used to treat…
heart conditions.
Give an exmaple of an antibiotic resistant bacterium.
MRSA
Super Gonorrhoae
What are the symptoms of gonorrhoae?
Pain when urinating
Thick yellow/green discharge from penis/vagina.
What type of cell is a protist?
A eukaryotic cell.
What has caused the development of antibitoic resistance?
Doctors over prescribing antibiotics
Farmers using antibiotics on animals
People not finishing the course of antibiotics.
The white blood cells that produce antibodies are sometimes called…
B-lymphocytes
What are the PROs of getting vaccinated?
Prevents disease spreading
Prevents epidemics
Eradicate diseases.
What are the CONs of vaccination?
They don’t always work.
You can have bad reacitons/side effects.
What does British law state with regard to testing drugs on animals?
All drugs must be tested on at least 2 mammals.
How can gonorrhoea be prevented from spreading?
Barrier contraception i.e. condoms.
What is meant by the optimum doase of a drug?
The dose at which it works best with the least side effects.
What are the symptoms of measles?
Red rash
Fever
Aspirin comes form which plant?
Willow tree bark
How do white blood cells protect us from pathogens?
Engulf to kill (Phagocytosis)
Produce antibodies to kill
Produce antitoxins to neutralise toxins.
The drug digitalis comes from which plant?
Foxglove
Describe what happens during a clinical trial.
- Volunteers randomly put into 2 groups.
- One group given drug other group given a dummy drug (placebo)
- Neither volunteers or Doctors know who has been given the real drug.
- This is called a double blind trial.
- This prevents the Drs and volunteers from subconciously affecting the results.
- If group given real drug gets better then results be peer reveiwed by other scientists.
How is the spread of salmonella reduced?
Chickens are vaccinated against the disease.
What does a vaccine contain?
A dead/weak/attenuated pathogen
Why do we test on human cells and tissues?
To check toxicity
To check efficacy
What is a ‘superbug’?
An antibiotic resistant bacterium
