IGCSE Biology glossary
Vector
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
In genetic engineering, a carrier molecule used to transfer a gene from one organism into another. The most common vector is a bacterial plasmid, but viruses can also be used. In disease biology, a vector is an organism (such as a mosquito) that transmits a pathogen from one host to another.
What to include in an exam answer
The word 'vector' has two meanings in IGCSE biology. In genetic engineering: a plasmid or virus that carries a gene. In disease: an organism that transmits a pathogen (e.g. Anopheles mosquito for malaria). Check the context carefully.
Example in context
In genetic engineering, state what is meant by a vector and give an example (2 marks): A vector is a carrier used to transfer a gene into a host organism. An example is a bacterial plasmid.
Related syllabus topic
Biotechnology & genetic modification