A Solid has a fixed mass.
There are two important regions of a lipid that provide the structure of the lipid bilayer. Each lipid molecule contains a hydrophilic region, also called a polar head region, and a hydrophobic, or nonpolar tail region
Answer:
Digestive
Explanation:
The by-products of digestion are solid waste which is removed through egestion.
The atmosphere
Is not a reservoir for phosphorus.
