Communicable (infectious) diseases Flashcards – AQA GCSE Combined Science: Trilogy (8464) — Biology — Foundation

What is a pathogen?

An organism that causes disease.

How can a pathogen cause illness after entering a host?

It can reproduce or act in ways that damage the body.

What makes a disease transmissible?

The pathogen causing it can pass from one host to another, allowing the disease to spread through a population.

Are all diseases caused by infectious organisms?

No. Not all diseases are caused by infectious organisms.

How does a clean water supply reduce disease transmission?

It prevents waterborne pathogens from being drunk or used in the home.

What two risks does hygienic food preparation reduce?

• Contamination of food with pathogens.
• Multiplication of pathogens in food.

How does good personal hygiene reduce disease transmission?

It lowers the chance of transferring pathogens between people, surfaces and food.

How does waste disposal reduce disease transmission?

It removes rubbish and other materials that could harbour pathogens or attract disease-spreading animals.

How does sewage treatment reduce disease transmission?

It reduces the release of human waste containing pathogens into the environment.

Why do hygiene and public health measures protect whole communities rather than just individuals?

They break transmission pathways, reducing the spread of pathogens through the community.

What does vaccination introduce into the body?

Weakened pathogens or their antigens.

What two things do vaccine antigens stimulate lymphocytes to produce?

Antibodies and memory cells.

How do memory cells formed after vaccination provide long-term immunity?

They allow a response to the pathogen on later exposure.

Why does protecting people from infection through vaccination help control disease spread?

It reduces opportunities for the pathogen to pass between hosts.