What is the definition of a pathogen and give two examples. (3 marks)
An organism that can cause disease - e.g. virus, bacterium, fungus
TR
Related Biology A Level answers
All answers ▸What is transcription?
How does the sequence of pressure changes in the heart produce a unidirectional flow of blood?
Describe the structure of a protein
Why do mutations makes it difficult to create a vaccine ? (4 marks - has the potential to be worth more in an exam)