C) slate, a metamorphic rock
<em>Answer:</em>
<em>Phospholipids form the basic structure of a cell membrane, called the lipid bilayer. Scattered in the lipid bilayer are cholesterol molecules, which help to keep the membrane fluid consistent. Membrane proteins are important for transporting substances across the cell membrane</em>
Answer:
2 membrane layers cover up the nucleus
The important role of the atmosphere is to supply oxygen, water, carbon dioxide and nutrients. It also protects all living things from extreme temperatures and radiation (protects us from harmful solar rays).
