Communicable (infectious) diseases Flashcards – AQA GCSE Biology - Foundation (8461)

What four types of pathogen can cause communicable diseases in animals and plants?

Viruses, bacteria, protists and fungi.

What is pathogen transmission?

The passage of a pathogen from an infected host or contaminated source to another host, where it can cause infection.

What determines the route by which a pathogen is transmitted?

The pathogen and the host.

What are three routes by which pathogens can be transmitted between hosts?

• Direct contact
• Contaminated water
• Airborne droplets or particles

How can isolating infected hosts or removing infected plants reduce transmission?

It limits contact with susceptible hosts, reducing opportunities for infection.

What are pathogenic bacteria?

Single-celled microorganisms that can infect a host.

How do pathogenic bacteria multiply?

Rapidly, by cell division.

What are bacterial toxins, and what effects do they have on a host?

Poisonous substances that damage host tissues and contribute to illness symptoms.

Besides producing toxins, how can bacterial populations harm a host?

Through their multiplication.

What are the two broad ways to reduce the spread of infectious disease?

Limit contact with pathogens or reduce the number of susceptible hosts.

How do handwashing and cleaning or disinfecting shared surfaces and tools reduce disease spread?

They remove or kill pathogens that could pass between animal or plant hosts.

How does water treatment reduce infectious disease spread?

It reduces the pathogens that water can carry.

How can ventilation reduce infectious disease spread?

It can reduce the accumulation of infectious airborne particles.

How can vaccination protect an animal host before exposure to a pathogen?

It stimulates an immune response before exposure.

How can vaccination reduce the spread of a pathogen between hosts?

By reducing infection or transmission, it gives the pathogen fewer opportunities to spread.

Does any single measure necessarily provide complete protection against infectious disease spread?

No single preventive measure necessarily provides complete protection.