The number of chromosomes

• what happens to the number of chromosomes in meiosis?

  the diploid number of chromosomes is halved to haploid
• what happens when 2 haploid gametes fuse at fertilisation?

  the zygote that is formed has 2 complete sets of chromosomes, one from each gamete, restoring the diploid condition
• what would happen if the chromosome number didn't halve during gamete formation?

  the number of chromosomes would double every generation, which would cause genetic abnormalities, affecting the health of the offspring