Answer:
Many people believe it to be unethical to remove/implant an embryo into a female, just as they see it unfitting to manipulate an individual when in an embryonic state.
Explanation:
The keystone species is the one at the bottom of the pyramid, if we look at it like a pyramid. If the grass dies, then the deer cannot get food and die, and the predator cannot eat and dies, and the whole ecosystem can fall apart.
Both glycerophospholipids and sphingolipid structures are asymmetrically distributed in the two layers of the phospholipid bilayer. Sphingolipids are membrane lipids that have a ceramide backbone while glycerophospholipid has glycerol present in its membrane lipids. Sphingolipids may or may not be present.