Prions are infectious proteins that are not classified as living organisms.
State two life processes that prions cannot carry out.
Name one disease in humans that is caused by a prion.
Plasmids are small, circular DNA molecules found in many bacteria, which are also not classified as independent living organisms.
Suggest two structural or functional differences between plasmids and typical viruses.
7 exam-style questions on Edexcel IGCSE Biology Characteristics of living organisms. Each one has a worked solution and a mark scheme showing where the marks go.