Egg coat proteins bind sperm and calcium waves activate development after fusion.
At fusion, a sperm factor (PLCζ) triggers calcium oscillations; cortical granules release enzymes that harden the zona and cleave ZP2. The egg resumes meiosis. Defects cause infertility.
Egg activation resumes the cell cycle and triggers metabolic changes. Failure leads to fertilisation failure.
Remember: calcium is the universal trigger.
Egg coat proteins bind sperm and calcium waves activate development after fusion.
Zona Pellucida and Egg Activation is one of the 54 topics in Reproduction & Endocrinology. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Sperm Capacitation and Acrosome Reaction, Implantation, Fertilisation Process.
Artificial egg activation uses calcium ionophores in some IVF cases.
Work through the Beginner topics in Reproduction & Endocrinology first, such as Reproduction, Asexual Reproduction, Sexual Reproduction, then return to Zona Pellucida and Egg Activation. Advanced topics assume the Intermediate vocabulary.
The closest topics to Zona Pellucida and Egg Activation are Sperm Capacitation and Acrosome Reaction, Implantation, Fertilisation Process, Female Reproductive System. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Zona Pellucida and Egg Activation. To practise the whole of Reproduction & Endocrinology, use the Reproduction & Endocrinology quiz.
Zona Pellucida and Egg Activation: Egg coat proteins bind sperm and calcium waves activate development after fusion. Sperm Capacitation and Acrosome Reaction: Sperm undergo biochemical changes that let them penetrate the egg's protective layers. Read both side by side and note what each one explains.
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Sperm Capacitation and Acrosome Reaction and explain the difference aloud. Finally, take the Reproduction & Endocrinology quiz and come back to this page for any question you miss.
Sperm undergo biochemical changes that let them penetrate the egg's protective layers.
🌸 Reproduction & EndocrinologyThe blastocyst embeds in the uterine lining about a week after fertilisation.
🌸 Reproduction & EndocrinologyThe sperm penetrates the egg, triggering the cortical reaction that blocks other sperm.
🌸 Reproduction & EndocrinologyOvaries release eggs and hormones; the uterus nurtures the developing embryo.
🌸 Reproduction & Endocrinology