Biology · Health and Communicable Disease
Knowledge organiser
The whole chapter on one page. Print it on A4 — it is already landscape — or cover a box and see how much of it you can say from memory.
Biology · OCR Paper 2
Health and Communicable Disease
Health and Disease
Health is physical and mental wellbeing, and diseases of different types are linked, because one disease can make another more likely.
- Health A state of physical and mental wellbeing, not only the absence of disease.
- Disease A condition that stops part of the body or mind from working properly.
- Pathogen A microorganism that causes disease.
Communicable and non-communicable disease
- Communicable disease Caused by a pathogen; Can be passed from one organism to another; Examples: flu, tuberculosis, malaria, athlete's foot
- Non-communicable disease Not caused by a pathogen; Cannot be passed on to another person; Examples: cystic fibrosis, scurvy, depression, type 2 diabetes
How Communicable Diseases Spread
A pathogen spreads when it gets from an infected host to a new host, so the route it takes is the thing to block.
- Pathogen A microorganism that causes disease.
- Virus A tiny particle that infects a host cell and uses it to make more viruses.
- Bacterium A single-celled organism with no nucleus that reproduces by binary fission.
Spread in animals and in plants
- In animals Direct contact, air, water, food and vectors; Coughs and sneezes release droplets; Vectors include mosquitoes and flies
- In plants Direct contact, wind, water, soil and vectors; Fungal spores are blown by the wind; Vectors include aphids