Question 1

Small nonpolar molecules, such as O2 and CO2, enter a cell by:

Accepted Answer

A)  active transport.
B)  osmosis.
C)  facilitated diffusion.
D)  vesicle-mediated transport.
E)  simple diffusion.

Question 2

A "gate" is most directly associated with a:

Accepted Answer

A)  pinocytosis.
B)  pump.
C)  vesicle
D)  carrier.
E)  channel.

Question 3

Pinocytosis is a form of endocytosis.

Accepted Answer

A) True 
 B)False

Question 4

In receptor-mediated endocytosis, what happens immediately after the substance to be transported binds to a receptor?

Accepted Answer

A)  The substance is broken down enzymatically.
B)  The coated pit invaginates to form a coated vesicle.
C)  The receptor releases the substance inside the cell.
D)  The coated vesicle sheds its coat.
E)  The receptor is broken down enzymatically.

Question 5

What is the hypothesized role of carbohydrates in the plasma membrane?

Accepted Answer

A)  catalyzing chemical reactions
B)  keeping the phospholipid tails aligned
C)  recognizing molecules that interact with the cell
D)  acting as a barrier to the passage of molecules
E)  transporting molecules into the cell

Question 6

The long-distance transport of sap in the phloem is an example of:

Accepted Answer

A)  simple diffusion.
B)  facilitated diffusion.
C)  pressure-driven bulk flow.
D)  active transport.
E)  exocytosis.

Question 7

Proteins and polysaccharides will most likely enter a cell by:

Accepted Answer

A)  active transport.
B)  osmosis.
C)  facilitated diffusion.
D)  vesicle-mediated transport.
E)  simple diffusion.

Question 8

Most membrane carbohydrates are present in the form of:

Accepted Answer

A)  glycoproteins.
B)  lectins.
C)  individual glucose molecules.
D)  starch.
E)  disaccharides.

Question 9

When a leaf wilts, the leaf cells most likely have already plasmolyzed.

Accepted Answer

A) True 
 B)False

Question 10

Which of the following statements concerning plasmodesmata is FALSE?

Accepted Answer

A)  They can mediate the transport of proteins and RNA.
B)  Their openings can be regulated by actin and myosin..
C)  They serve as paths for electrical signaling.
D)  Their permeability can be controlled by callose.
E)  Their similar symplastic domains cause them to be passive structures.

Question 11

Symport is a transport system in which the transport of one solute:

Accepted Answer

A)  occurs via a vesicle.
B)  occurs without the simultaneous transport of another solute.
C)  depends on the transport of another solute in the opposite direction.
D)  depends on the transport of another solute in the same direction.
E)  depends on the opening of a "gate" in the carrier protein.

Question 12

Passive diffusion can occur down a concentration gradient but not down an electrochemical gradient.

Accepted Answer

A) True 
 B)False

Question 13

Suppose a drop of dye is placed in one end of a tank of water.What happens next?

Accepted Answer

A)  Nothing happens because the molecules are at equilibrium.
B)  The dye molecules and the water molecules move down their respective concentration gradients.
C)  The dye molecules move from a region of high water potential to a region of low water potential.
D)  The dye molecules move against a concentration gradient.
E)  The water molecules move by osmosis.

Question 14

In the absence of other factors affecting water potential, water will move FROM a region of ______ TO a region of ______.

Accepted Answer

A)  low water concentration; high water concentration
B)  low solute concentration; high solute concentration
C)  low water potential; high water potential
D)  low potential energy; high potential energy
E)  low pressure; high pressure

Question 15

Water potential is defined as the:

Accepted Answer

A)  tendency of water to enter a cell.
B)  tendency of water to leave a cell.
C)  mechanical energy of water.
D)  kinetic energy of water.
E)  potential energy of water.

Question 16

Aquaporins are found in the plasma membrane and the:

Accepted Answer

A)  inner mitochondrial membrane only.
B)  inner chloroplast membrane only
C)  tonoplast only.
D)  endoplasmic reticulum only.
E)  the mitochondrial membrane, the chloroplast membrane, the tonoplast, and the ER.

Question 17

A protein would most likely enter a cell by simple diffusion.

Accepted Answer

A) True 
 B)False

Question 18

Once inside a cell, an ion will move from one part of the cytoplasm to another by diffusion.

Accepted Answer

A) True 
 B)False

Question 19

Wilting results most directly from _______ in plant cells.

Accepted Answer

A)  increased metabolism
B)  malfunctioning contractile vacuoles
C)  the loss of turgor
D)  defective osmotic pressure
E)  defective membranes

Question 20

Two of the most common second messengers are:

Accepted Answer

A)  hormones and ATP.
B)  ATP and cyclic AMP.
C)  calcium ions and cyclic AMP.
D)  lectins and calcium ions.
E)  lectins and clathrin.

Exam 4: The Movement of Substances Into and Out of Cells

Passive diffusion can occur down a concentration gradient but not down an electrochemical gradient.

Correct AnswerverifiedShow Answer

Which of the following statements concerning plasmodesmata is FALSE?

Correct AnswerverifiedShow Answer

What is the hypothesized role of carbohydrates in the plasma membrane?

Correct AnswerverifiedShow Answer

A protein would most likely enter a cell by simple diffusion.

Correct AnswerverifiedShow Answer

In receptor-mediated endocytosis, what happens immediately after the substance to be transported binds to a receptor?

Correct AnswerverifiedShow Answer

Wilting results most directly from _______ in plant cells.

Correct AnswerverifiedShow Answer

The long-distance transport of sap in the phloem is an example of:

Correct AnswerverifiedShow Answer

Pinocytosis is a form of endocytosis.

Correct AnswerverifiedShow Answer

In the absence of other factors affecting water potential, water will move FROM a region of ______ TO a region of ______.

Correct AnswerverifiedShow Answer

Suppose a drop of dye is placed in one end of a tank of water.What happens next?

Correct AnswerverifiedShow Answer

Most membrane carbohydrates are present in the form of:

Correct AnswerverifiedShow Answer

Proteins and polysaccharides will most likely enter a cell by:

Correct AnswerverifiedShow Answer

Small nonpolar molecules, such as O2 and CO2, enter a cell by:

Correct AnswerverifiedShow Answer

Symport is a transport system in which the transport of one solute:

Correct AnswerverifiedShow Answer

When a leaf wilts, the leaf cells most likely have already plasmolyzed.

Correct AnswerverifiedShow Answer

Two of the most common second messengers are:

Correct AnswerverifiedShow Answer

Once inside a cell, an ion will move from one part of the cytoplasm to another by diffusion.

Correct AnswerverifiedShow Answer

Water potential is defined as the:

Correct AnswerverifiedShow Answer

A "gate" is most directly associated with a:

Correct AnswerverifiedShow Answer

Aquaporins are found in the plasma membrane and the:

Correct AnswerverifiedShow Answer

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In the absence of other factors affecting water potential, water will move FROM a region of TO a region of .

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Small nonpolar molecules, such as O₂ and CO₂, enter a cell by:

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