Explain the role of meiosis in halving the chromosome number to form gametes in reproductive organs.
Describe the stages of meiosis: genetic replication followed by two cellular divisions to produce four genetically distinct gametes with single chromosome sets.
Understand that fertilisation restores the full, normal number of chromosomes in the resulting zygote.
Explain how the newly formed zygote divides rapidly by mitosis to increase cell number, followed by cellular differentiation as the embryo develops.
