Integral proteins have both a hydrophobic region and hydrophilic region. The hydrophobic region allows them to sit within the cell membrane, while their hydrophilic regions face the aqueous solutions on either side of the membrane.

An amphipathic molecule is one that has both hydrophilic and hydrophobic regions. In the case of phospholipids, the tail is hydrophobic and the head is hydrophilic. 

Isotonic is the correct term to describe solutions with equal solute concentrations. The root word "iso" means same; therefore, isotonic solutions have the same concentration of solute. A hypotonic solution will have less solute in it. A hypertonic solution will have a higher concentration of solute between the two solutions.

Endocytosis is the process by which the cell takes in macromolecules by forming vesicles from the plasma membrane to carry the molecules into the cell. Exocytosis, on the other hand, is the opposite. This is the process by which cells use vesicles to secrete substances from the cell. Phagocytosis, pinocytosis, and receptor-mediated endocytosis are all types of endocytosis.  

Solution B is hypotonic to solution A. Solution B is hypotonic because it has an overall lower number of solutes in it even though it has more types of solutes in it. Diversity of the solutes does not not matter when comparing concentrations of solutions, only the overall number of solutes matters. Tonicity can be thought of as relative concentration. Remember that a solution cannot simply be hypertonic or hypotonic; its concentration must be compared to that of another solution.

Solution A is isotonic to solution B. This means that both solutions are equal in terms of concentration. Even though solution B has a greater variety of solutes in it, both solutions have the same overall concentration, and thus tonicity. When deciding whether a solution is hypertonic, hypotonic, or isotonic to another solution only consider the overall number of solutes in the solutions not the types of solutes.  

The cell will lose water, shrink, and most likely die. When a cell is placed in a solution that is hypertonic to it, water will flow from the hypotonic inside of the cell to the hypertonic environment outside the cell. This causes the cell to shrink from water lost and die. Remember that water follows solutes.

Active transport occurs when the cell uses energy to pump molecules into and out of the cell against their concentration gradients. Passive transport occurs when molecules into and out of the cell down their concentration gradients and so no energy is used. Facilitated diffusion involves a protein carrier or channel facilitating the diffusion of a molecule across the plasma membrane, down its concentration gradient. Osmosis is the diffusion of water.  

Exocytosis is the process by which the cell secretes macromolecules. In this process a transport vesicle from the Golgi apparatus moves to and fuses with the plasma membrane by rearranging the lipid molecules of the two membranes. This in turn pushes the contents of the vesicle outside of the cell. Pinocytosis and phagocytosis are both types of endocytosis.  

Solution A is hypertonic to solution B. Solution A is hypertonic because it has an overall higher number of solutes in it even though B has more types of solutes in it. Diversity of the solutes does not matter when comparing concentrations of solutions, only the overall number of solutes matters. Tonicity can be thought of as relative concentration. Remember that a solution cannot simply be hypertonic or hypotonic; its concentration must be compared to that of another solution.