IGCSE Biology glossary
Zygote
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Definition
The cell formed when two haploid gametes fuse at fertilisation. The zygote is diploid, containing the full number of chromosomes (46 in humans, with 23 from each parent). It divides by mitosis to develop into an embryo.
What to include in an exam answer
The zygote is the first cell of a new organism. It is diploid. It divides by mitosis (not meiosis) to form an embryo. Make sure to distinguish zygote (single cell) from embryo (many cells).
Example in context
Define the term zygote (1 mark): A diploid cell formed by the fusion of the nuclei of two haploid gametes at fertilisation.
Related syllabus topic
Reproduction