Infection and Response Flashcards
What are pathogens?
Microorganisms that cause infectious diseases.
What are some ways that pathogens are spread?
Direct contact, water, air, vectors.
What is a vector?
Organisms that carry and pass on a disease without getting infected, themselves.
What are the four main types of diseases?
Viruses, protists, bacteria, fungi.
Give an example of a viral disease.
Measles - fever and rash, spread through the air in water droplets.
HIV/AIDS - attacks immune system, spread through bodily fluids.
Tobacco mosaic virus - discolouration reduces chlorophyll content in the leaves, affecting photosynthesis and plant growth.
What happens if a plant gets tobacco mosaic virus (TMV)?
The discolouration in leaves reduces chlorophyll content which affects photosynthesis and plant growth.
What are features of bacterial diseases?
They damage cells and may produce poisons which damage tissues.
What is an example of a bacterial disease?
Salmonella - food poisoning caused by bacteria, which leads to vomiting, cramps and diarrhoea.
Gonorrhoea - STD caused by bacteria.
What type of cell is bacteria?
Prokaryotic.
What type of organism is a protist?
Single-celled, eukaryotic.
What type of disease is malaria?
Protist disease, caused by a mosquito (vector) carrying it.
What is an example of a fungal disease in plants?
Rose black spot - results in a loss of leaves, which stunts growth and photosynthesis.
Give a few examples of non-specific defences against disease.
Sheets of mucus trap particles and bacteria.
Enzymes in tears destroy microorganisms.
Glands produce hydrochloric acid. which kills bacteria in food.
Describe the process of phagocytosis.
White blood cells finds the invading microorganisms, engulfs them and then digests and destroys them.
What are antibodies?
Special protein molecules which attach to the antigen molecules on pathogens and causes them to clump together so that the white blood cells can digest them.
What are antibodies?
Chemicals that neutralise the poisonous effects of toxins.
What is immunity?
When white blood cells are familiar with the invading pathogens and produces the correct antibodies faster.
What is a vaccination?
When small quantities of dead or inactive forms of pathogens are injected into the body to stimulate white blood cells to produce antibodies and develop immunity.
What is herd immunity?
When certain percentage of the population is immune (usually vaccinated) against a certain disease, so it can’t spread.
How does the stomach help kill pathogens?
Glands in the stomach wall produce hydrochloric acid, which kill bacteria in food.
What are antibiotics?
Medicines that kill bacteria inside the body.
What are examples of antibiotics?
Penicillin.
How should we reduce strains of bacteria that are resistant to antibiotics?
Doctors should not prescribe antibiotics unless they are really needed, for non-serious infections or for viral infections.
Patients should also complete their full course of antibiotics so that none survive to form resistant strains.
What heart drug originates from foxgloves?
Digitalis.
What plant does aspirin originate from?
Willow.
How was penicillin discovered and who discovered it?
Alexander Fleming discovered it from a type of mould.
After testing and after it is found to be safe, why is a new drug tested on patients?
To see if it works.
To find the optimum dose.
What are double-blind trials?
When neither doctor nor patient know of the drug is the real thing or a placebo.
Why are new antiviral drugs difficult to synthesise?
As these drugs would have to kill the viruses without damaging the body’s tissue.
What is a placebo?
A fake drug designed to weed out which responses are psychosomatic and which are genuine responses to an actual drug. These are usually super tablets.
