<span>The formation of the fertilization envelope (slow-block to polyspermy) requires an increase in the availability of </span>calcium ions.
Slow-block to polyspermy is also called cortical reaction. In this reaction, the sperm will be permanently blocked by cortical granules. The release of calcium ion will trigger this reaction.
Answer:
D
Explanation:
There are many food chains within a food web, so D seems like the best possible answer :)
Answer:
They reproduce quickly in your body. Many give off chemicals called toxins, which can damage tissue and make you sick.
Hope this helps!
Fossils give information about the time period in which organisms lived in the past.