I think it’s the first one
Answer:
Sperm-egg interaction
Explanation:
The formation of fertilization envelope is well-studied on the model system- sea urchin. It has been shown that, the fertilization envelope is formed after the initial sperm-egg interaction from the egg surface vitelline envelope and the paracrystalline protein fraction which is derived from cortical granules. Secretion from cortical granules, prevents polyspermy.
Answer:
Explanation:
The skeletal system
The skeletal system works as a support structure for your body. It gives the body its shape, allowing movement.
