International A Level Biology / Mitosis, meiosis and reproduction

Fertilisation in mammals revision notes

Edexcel International A Level Biology (YBI11), chapter 8: Mitosis, meiosis and reproduction, specification point 3.12. Part of the full course.

Watch the video lesson · International A Level Biology past papers

Fertilisation is the joining of a sperm and egg in the oviduct. The acrosome and cortical reactions help sperm enter the egg and prevent more than one sperm fertilising it, before the two nuclei fuse to form a diploid zygote.

More lessons in Mitosis, meiosis and reproduction

• The cell cycle
• The stages of mitosis
• Core practical 6: the root tip squash
• Calculating the mitotic index
• Meiosis: two divisions, four haploid cells
• Independent assortment and crossing over
• Loci and linked genes
• Sperm and egg: specialised gametes
• Fertilisation in flowering plants
• Investigating pollen tube growth