Biology for IGCSE & O level - Inheritance (Section 4 - No. 29)

What does the term 'carrier' mean in the context of human genetics?

Someone affected by the disease

Someone who has the dominant allele.

Someone who is heterozygous for a recessive allele.

Someone who is homozygous for a recessive allele.

A carrier is heterozygous, and does not express the disease, but carries the recessive allele.