Biology 2015

In the fluid-mosaic model, the fluid properties are associated with the nature of the ______ and the mosaic pattern is established by the _______.
a. nucleic acids; phospholipids
b. phospholipids; embedded proteins
c. embedded proteins; cholesterol
d. phospholipids; nucleic acids

Which of the following is not a function of proteins present in the plasma membrane?
a. Proteins assist the passage of materials into the cell.
b. Proteins interact with and recognize other cells.
c. Proteins bind with specific hormones.
d. Proteins carry out specific metabolic reactions.
e. Proteins produce lipid molecules.

The carbohydrate chains projecting from the plasma membrane are involved in
a. adhesion between cells. $\quad$ c. cell-to-cell recognition.
b. reception of molecules. $\quad$ d. All of these are correct.

When a cell is placed in a hypotonic solution,
a. solute exits the cell to equalize the concentration on both sides of the membrane.
b. water exits the cell toward the area of lower solute concentration.
c. water enters the cell toward the area of higher solute concentration.
d. there is no net movement of water or solutes.

When a cell is placed in a hypertonic solution,
a. solute exits the cell to equalize the concentration on both sides of the membrane.
b. water exits the cell toward the area of lower solute concentration.
c. water exits the cell toward the area of higher solute concentration.
d. there is no net movement of water or solute.

A plant cell that is placed in a hypertonic solution would experience
a. crenation.
b. an increase in turgor pressure.
c. plasmolysis.
d. no net changes.

Which of the following is incorrect regarding facilitated diffusion?
a. It is a passive process.
b. It allows the movement of molecules from areas of low concentration to areas of high concentration.
c. It may use either channel or carrier proteins.
d. It allows the rapid transport of glucose across the membrane

The sodium-potassium pump
a. helps establish an electrochemical gradient across the membrane.
b. concentrates sodium on the outside of the membrane.
c. uses a carrier protein and chemical energy.
d. is present in the plasma membrane.
e. All of these are correct.

Which of the following processes is involved in the bulk transport of molecules out of the cell?
a. phagocytosis
b. pinocytosis
c. receptor-mediated endocytosis
d. exocytosis
e. None of these are correct.

Which process uses special proteins on the surface of the membrane to identify specific molecules for transport into the cell?
a. phagocytosis
b. pinocytosis
c. receptor-mediated endocytosis
d. exocytosis

The extracellular matrix
a. assists in the movement of substances across the plasma membrane.
b. prevents the loss of water when cells are placed in a hypertonic solution.
c. has numerous functions that affect the shape and activities of the cell that produced it.
d. contains the junctions that sometimes occur between cells.
e. All of these are correct.

Which of the following junctions allows for cytoplasm-tocytoplasm communication between cells?
a. adhesion junctions
b. tight junctions
c. gap junctions
d. None of these are correct.