<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.
George Monbiot is spearheading the Rewilding Movement. The environmentalist and writer is prominent in the platform. He was featured in TED Talk and talked about a large scale conservation approach aiming to restore the lost habitats. Here is an excerpt of his speech where he discusses the lost megafuna:
"What megafauna, you say? Well, every continent had one, apart from Antarctica. When Trafalgar Square in London was excavated, the river gravels there were found to be stuffed with the bones of hippopotamus, rhinos, elephants, hyenas, lions. Yes, ladies and gentlemen, there were lions in Trafalgar Square long before Nelson's Column was built. All these species lived here in the last interglacial period, when temperatures were pretty similar to our own. It's not climate, largely, which has got rid of the world's megafaunas. It's pressure from the human population hunting and destroying their habitats which has done so."
Answer:
The answer is D because it is the only example that takes place over a long period of time.
Explanation:
Answer: true
Explanation: the upper part (scion) of one plant grows on the root system (rootstock) of another plant. In the budding process, a bud is taken from one plant and grown on another.
