BIO 121 PRE-TEST EXAM 2025
QUESTION AND ANSWERS
Which of the following statements about diffusion is true?
A. It requires expenditure of energy by the cell.
B. It occurs when molecules move from a region of lower concentration to a
region of higher concentration.
C. It is very rapid over long distances.
D. It is a passive process
E. It always requires integral proteins of the cell membrane
D
Requires no energy! Molecules follow a concentration gradient spreading out from a
region of high concentration and moving into a region of low concentration.
Which of the following is a correct difference between active transport and
facilitated diffusion?
A. Active transport requires energy from ATP, and facilitated diffusion does not.
B. Active transport can move solutes in either direction across a membrane, but
facilitated diffusion can only move in one direction.
C. Facilitated diffusion can move solutes against a concentration gradient, and
active transport cannot.
D. Active transport involves transport proteins, and facilitated diffusion does not.
E. Facilitated diffusion involves transport proteins, and active transport does not.
A.
Active transport requires energy input (ATP hydrolysis) to power the movement of
molecules, typically the movement is against the concentration gradient
Which of the following statements about the sodium-potassium pump is correct?
A. The sodium-potassium pump is an antiproton that results in a net negative
charge inside the cell.
B. The sodium-potassium pump is a symporter that results in a net negative
charge outside the cell.
C. The sodium-potassium pump moves sodium out of the cell and co-transports
protons into the cell, which is the source of energy for the movement of the
potassium into the cell.
D. The sodium-potassium pump uses an existing proton gradient to drive the
movement of sodium and potassium ions.
E. The sodium-potassium pump transports Na+ and K+ across the plasma
membrane in the same direction at the expense of ATP hydrolysis
A.
Sodium (3+) moves out of the cell, and Potassium (2+) moves into the cell. Each of
,these movements are against the concentration gradient and this requiring active
transport. The net result of this transport is a charge difference making the inside of the
cell more electronegative.
Which of the following statements about cotransport of solutes across a
membrane is correct?
A. A cotransport protein is most commonly an ion channel.
B. Cotransport involves the hydrolysis of ATP by the transporting protein.
C. Cotransport proteins allow a single ATP-powered pump to drive the active
transport of many different solutes.
D. The sodium-potassium pump is an example of a cotransport protein.
E. In cotransport, both solutes that are being transported are moving down their
chemical gradients.
C.
A single ATP powered pump transports hydrogen against it's concentration gradient to
the outside of the cell. This hydrogen ion gradient can then be coupled with the
transport of several other solutes to provide the needed energy to bring them into the
cell
Which of the following enables a cell to pick up and concentrate a specific kind of
molecule?
A. facilitated diffusion
B. osmosis
C. passive transport
D. receptor-mediated endocytosis
E. channel proteins
D.
Receptor mediated endocytosis allows a cell to acquire bulk quantities of a specific
substance
Which of the following categories best describes the function go the rough
endoplasmic reticulum?
A. energy production
B. information storage
C. breakdown of complex foods
D. structural support of cells
E. protein production
E.
Rough ER is so called because it is decorated with ribosomes. These ribosomes are
producing new proteins for the cell which are injected into the ER lumen or span the ER
membrane.
Which of the following five membranes is the most likely to have a lipid
composition that is distinct from the other four?
, A. mitochondrial outer membrane
B. plasma membrane
C. lysosome membrane
D. endoplasmic reticulum E. Golgi apparatus
A.
The mitochondrial membrane originates from the replication/splitting of existing
mitochondria. All the other membranes mentioned are formed from movement of lipids
away from the endoplasmic membrane, thus they would all have similar composition.
Which of the following structures is found in animal cells but NOT plant cells?
A. Golgi apparatus
B. rough endoplasmic reticulum
C. centrioles
D. plasma membrane
E. mitochondria
C.
Despite a well organized microtubule system the plant cell and some fungi actually lack
centrioles
At body temperature (37 C), a very fluid plasma membrane would be composed of
primarily,_____?
A. large amounts of cholesterol
B. Phospholipids with saturated hydrocarbon tails
C. phospholipids which have been glycosylated
D. Phospholipids with unsaturated hydrocarbon tails
D.
Unsaturated hydrocarbon tails cause the molecule to "kink" thus blocking the
phospholipids from packing tightly together. This loose arrangement of phospholipids
caused by the unsaturated tails greatly increases membrane fluidity.
Consider the currently accepted fluid mosaic model of the plasma membrane.
Where in the membrane would carbohydrates most likely be found?
A. on the outside (external) surface of the membrane
B. in the interior of the membrane
C. on both hydrophilic surfaces of the membrane but not in the hydrophobic
interior
D. Carbohydrates are rarely associated with plasma membranes.
E. on the inside (cytoplasmic) surface of the membrane
A.
Carbohydrates are added to proteins which face the inside of the Golgi complex. As
QUESTION AND ANSWERS
Which of the following statements about diffusion is true?
A. It requires expenditure of energy by the cell.
B. It occurs when molecules move from a region of lower concentration to a
region of higher concentration.
C. It is very rapid over long distances.
D. It is a passive process
E. It always requires integral proteins of the cell membrane
D
Requires no energy! Molecules follow a concentration gradient spreading out from a
region of high concentration and moving into a region of low concentration.
Which of the following is a correct difference between active transport and
facilitated diffusion?
A. Active transport requires energy from ATP, and facilitated diffusion does not.
B. Active transport can move solutes in either direction across a membrane, but
facilitated diffusion can only move in one direction.
C. Facilitated diffusion can move solutes against a concentration gradient, and
active transport cannot.
D. Active transport involves transport proteins, and facilitated diffusion does not.
E. Facilitated diffusion involves transport proteins, and active transport does not.
A.
Active transport requires energy input (ATP hydrolysis) to power the movement of
molecules, typically the movement is against the concentration gradient
Which of the following statements about the sodium-potassium pump is correct?
A. The sodium-potassium pump is an antiproton that results in a net negative
charge inside the cell.
B. The sodium-potassium pump is a symporter that results in a net negative
charge outside the cell.
C. The sodium-potassium pump moves sodium out of the cell and co-transports
protons into the cell, which is the source of energy for the movement of the
potassium into the cell.
D. The sodium-potassium pump uses an existing proton gradient to drive the
movement of sodium and potassium ions.
E. The sodium-potassium pump transports Na+ and K+ across the plasma
membrane in the same direction at the expense of ATP hydrolysis
A.
Sodium (3+) moves out of the cell, and Potassium (2+) moves into the cell. Each of
,these movements are against the concentration gradient and this requiring active
transport. The net result of this transport is a charge difference making the inside of the
cell more electronegative.
Which of the following statements about cotransport of solutes across a
membrane is correct?
A. A cotransport protein is most commonly an ion channel.
B. Cotransport involves the hydrolysis of ATP by the transporting protein.
C. Cotransport proteins allow a single ATP-powered pump to drive the active
transport of many different solutes.
D. The sodium-potassium pump is an example of a cotransport protein.
E. In cotransport, both solutes that are being transported are moving down their
chemical gradients.
C.
A single ATP powered pump transports hydrogen against it's concentration gradient to
the outside of the cell. This hydrogen ion gradient can then be coupled with the
transport of several other solutes to provide the needed energy to bring them into the
cell
Which of the following enables a cell to pick up and concentrate a specific kind of
molecule?
A. facilitated diffusion
B. osmosis
C. passive transport
D. receptor-mediated endocytosis
E. channel proteins
D.
Receptor mediated endocytosis allows a cell to acquire bulk quantities of a specific
substance
Which of the following categories best describes the function go the rough
endoplasmic reticulum?
A. energy production
B. information storage
C. breakdown of complex foods
D. structural support of cells
E. protein production
E.
Rough ER is so called because it is decorated with ribosomes. These ribosomes are
producing new proteins for the cell which are injected into the ER lumen or span the ER
membrane.
Which of the following five membranes is the most likely to have a lipid
composition that is distinct from the other four?
, A. mitochondrial outer membrane
B. plasma membrane
C. lysosome membrane
D. endoplasmic reticulum E. Golgi apparatus
A.
The mitochondrial membrane originates from the replication/splitting of existing
mitochondria. All the other membranes mentioned are formed from movement of lipids
away from the endoplasmic membrane, thus they would all have similar composition.
Which of the following structures is found in animal cells but NOT plant cells?
A. Golgi apparatus
B. rough endoplasmic reticulum
C. centrioles
D. plasma membrane
E. mitochondria
C.
Despite a well organized microtubule system the plant cell and some fungi actually lack
centrioles
At body temperature (37 C), a very fluid plasma membrane would be composed of
primarily,_____?
A. large amounts of cholesterol
B. Phospholipids with saturated hydrocarbon tails
C. phospholipids which have been glycosylated
D. Phospholipids with unsaturated hydrocarbon tails
D.
Unsaturated hydrocarbon tails cause the molecule to "kink" thus blocking the
phospholipids from packing tightly together. This loose arrangement of phospholipids
caused by the unsaturated tails greatly increases membrane fluidity.
Consider the currently accepted fluid mosaic model of the plasma membrane.
Where in the membrane would carbohydrates most likely be found?
A. on the outside (external) surface of the membrane
B. in the interior of the membrane
C. on both hydrophilic surfaces of the membrane but not in the hydrophobic
interior
D. Carbohydrates are rarely associated with plasma membranes.
E. on the inside (cytoplasmic) surface of the membrane
A.
Carbohydrates are added to proteins which face the inside of the Golgi complex. As
