Expanded infection and response full set

What is a pathogen?

A microorganism that causes disease.

What are the four main types of pathogens?

Bacteria, viruses, fungi, and protists.

How do bacteria make us feel ill?

They produce toxins that damage tissues.

How do viruses cause disease?

They reproduce inside cells, damaging or destroying them.

How are pathogens spread?

Through air, water, direct contact, or vectors.

What is a communicable disease?

A disease that can be spread from one organism to another.

How can we reduce the spread of infectious disease?

Good hygiene, vaccination, isolating infected individuals, and destroying vectors.

Give an example of a bacterial disease.

Salmonella or gonorrhoea.

What are the symptoms of salmonella?

Stomach cramps, vomiting, and diarrhoea.

How is salmonella spread?

By eating contaminated food or contact with infected animals.

How is salmonella controlled in the UK?

Poultry are vaccinated against it.

What is gonorrhoea?

A sexually transmitted bacterial infection.

What are the symptoms of gonorrhoea?

Thick yellow/green discharge and pain when urinating.

How is gonorrhoea spread?

Through unprotected sexual contact.

How is gonorrhoea treated?

With antibiotics, although some strains are resistant.

Give an example of a viral disease.

Measles, HIV, or TMV (tobacco mosaic virus).

What are the symptoms of measles?

Fever and a red skin rash.

How is measles spread?

By inhaling droplets from coughs and sneezes.

What can measles lead to in severe cases?

Pneumonia or brain damage.

How is measles controlled?

By vaccination, especially in children.

What is HIV?

A virus that attacks the immune system.

How is HIV spread?

Through sexual contact or exchange of bodily fluids.

What can untreated HIV lead to?

AIDS, where the immune system is too weak to fight infections.

How is HIV controlled?

With antiretroviral drugs.

What is TMV (Tobacco Mosaic Virus)?

A virus that affects plants like tomatoes and tobacco.

What does TMV do to plants?

It causes a mosaic pattern on leaves and reduces photosynthesis.

Give an example of a fungal disease.

Rose black spot.

What are the symptoms of rose black spot?

Black spots on leaves which then turn yellow and drop off.

How is rose black spot spread?

By water or wind.

How is rose black spot treated?

By removing infected leaves and using fungicides.

Give an example of a disease caused by a protist.

Malaria.

What is a protist?

A single-celled eukaryotic organism, some of which are parasites.

How is malaria spread?

By mosquitoes

How can malaria be controlled?

By preventing mosquito bites using nets and killing mosquitoes.

What are the symptoms of malaria?

Repeating episodes of fever and can be fatal.

What is the first line of defence against pathogens?

Skin, nose hairs, mucus, and stomach acid.

How does the skin protect the body?

It acts as a physical barrier and produces antimicrobial secretions.

How does the nose protect us?

Hairs and mucus trap pathogens.

What does the trachea and bronchi do to protect us?

Produce mucus and have cilia to move it out.

How does the stomach protect us?

It produces hydrochloric acid to kill pathogens.

What is the role of the immune system?

To destroy pathogens that enter the body.

What are white blood cells?

Cells that defend the body against pathogens.

How do white blood cells defend the body?

By phagocytosis, producing antibodies, and producing antitoxins.

What is phagocytosis?

When a white blood cell engulfs and digests a pathogen.

What are antibodies?

Proteins made by white blood cells to target specific pathogens.

What are antitoxins?

Chemicals produced by white blood cells to neutralise toxins.

Why is it useful that antibodies are specific?

They only bind to one type of antigen, ensuring targeted defence.

What is vaccination?

Injecting small amounts of dead or inactive pathogens to stimulate an immune response.

How do vaccines protect you?

They help your body produce memory cells that respond quickly if infected again.

Why are vaccinations important?

They prevent outbreaks and protect communities (herd immunity).

What are the advantages of vaccination?

Control of disease, herd immunity, and reduced spread.

What are the disadvantages of vaccination?

May cause mild side effects and are not always 100% effective.

What is an antibiotic?

A drug that kills bacteria without harming body cells.

Why don’t antibiotics work on viruses?

Viruses live inside cells and are not affected by antibiotics.

What is antibiotic resistance?

When bacteria evolve and are no longer killed by antibiotics.

How can we slow the development of antibiotic resistance?

Avoid overusing antibiotics and finish full courses.

What is a painkiller?

A drug that treats symptoms but doesn’t kill pathogens.

Give examples of painkillers.

Paracetamol and aspirin.

Where was penicillin discovered?

In mould by Alexander Fleming.

What is digitalis and where is it from?

A heart drug developed from foxglove plants.

What is aspirin and where is it from?

A painkiller originally from willow bark.

Why do drugs need to be tested?

To check they are safe and effective.

What are the stages of drug testing?

Preclinical testing → Clinical trials → Double blind trials.

What is preclinical testing?

Testing drugs on cells, tissues, and animals.

What are clinical trials?

Testing drugs on healthy volunteers and patients.

What is a double-blind trial?

Neither the doctor nor patient knows who has the real drug or placebo.

Why are double-blind trials used?

To remove bias in testing the drug’s effectiveness.

What is a placebo?

A fake drug used to test the effectiveness of a real one.