Gravity is the attractive pull between two objects that have mass. The strength of gravity is directly proportional to the amount of mass of each object. ... An object with twice as much mass will exert twice as much gravitational pull on other objects. The gravitational force increases as the size of an object increases
The cell membrane is a lipid bilayer made of amphipathic phospholipids, which is fluid and selectively permeable to ions and organic molecules, given that the inside of the cell membrane is hydrophobic and the outside is hydrophilic.
The physical characteristics of the cell membrane, along with the proteins and other biomolecules embedded in it, control what enters and leaves the cell.
What the cell membrane DOESN'T do, is control the nucleus of the cell.
The answer is c. proteins
Molecules that are hydrophilic (water loving) are capable of forming bonds with water and other hydrophilic molecules. They are called polar molecules. ... Small, nonpolar molecules (ex: oxygen and carbon dioxide) can pass through the lipid bilayer and do so by squeezing through the phospholipid bilayers.