Question

Which of the following best describes a feature of the cell membrane's structure that allows molecules such as oxygen and hydrocarbons to easily cross the membrane and enter the cell?
a. The bilayer contains mostly polar molecules.
b. The interior of the lipid bilayer is hydrophobic.
c. The bilayer is embedded with transport proteins.
d. The exterior of the lipid bilayer is unsaturated.

Answer 1

B the interior of the phospholipid bilayer membrane is hydrophobic.  

the heads of the phospholipids are hydrophilic and the 2 tails are hydrophobic.
 
the molecules described are small enough that they can pass through the membrane without much trouble.   

Answer 2

Answer:

The interior of the lipid bilayer is hydrophobic (Ans. B)

Explanation:

The plasma membrane is selective in nature some of polar molecules and hydrophobic molecules can pass through the lipid bilayer of the cell membrane, large polar molecules and ions cannot pass through it.

By active and passive transport integral membrane proteins enables large polar molecules and ions to pass through the membrane. 3 primary factors which determine weather a molecule can diffuse through a membrane or not are : Size, Concentration and Charge.