What is a pathogen?
An organism that causes disease.
AQA GCSE Combined Science: Trilogy (8464) — Biology — Foundation · 4.3.1.1
Revise AQA GCSE Combined Science: Trilogy (8464) — Biology — Foundation specification point 4.3.1.1, Communicable (infectious) diseases, with free active-recall flashcards. Flip through the set or review every question and answer below.
1 / 23
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?
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.
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?
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.