IGCSE Biology glossary
Nucleus
Biology editorial review is supported by the named review panel. Reviewer participation may vary by guide. Checked against Cambridge IGCSE Biology 0610 (2026–2028); last reviewed August 2026.
Definition
A large organelle enclosed by a nuclear envelope that contains the cell's chromosomes, made of DNA. It controls the activities of the cell by determining which proteins are made.
What to include in an exam answer
Say the nucleus 'contains genetic material as chromosomes/DNA' and 'controls cell activities'. Avoid saying it is 'the brain of the cell' as this is not accepted.
Example in context
State two functions of the nucleus (2 marks): It contains the genetic material (DNA/chromosomes) and it controls the activities of the cell.
Related syllabus topic
Organisation of the organism