IGCSE Coordinated Science Vocabulary Practice Test 2026 - Free Coordinated Science Vocabulary Practice Questions and Study Guide

Sexual reproduction involves combining genetic material from two parents through the fusion of haploid gametes to form a diploid zygote. Because each gamete carries a different mix of alleles and fertilization brings together chromosomes from two individuals, the offspring are genetically dissimilar from each other and from either parent. This genetic variation arises from the processes that produce gametes (like meiosis with crossing over and independent assortment) and from the random nature of which sperm fertilizes which egg.

The other forms described are asexual: they start from a single parent and produce offspring genetically identical or very similar, without the fusion of two gametes, so they don’t create a zygote or genetic variation through combined parental genomes.