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BIOL 1P91 MIDTERM EXAM QUESTIONS AND
ANSWERS 2025
All of the following statements about membrane fluidity
are true EXCEPT:
a. shorter fatty acid tails increase membrane fluidity
b. saturated fatty acid tails make the membrane more
fluid
c. membrane fluidity is affected by the presence of
double-bonds in the fatty acid tails
d. at high temperatures, cholesterol makes the
membrane less fluid - .....ANSWER... ✔✔ b. saturated
fatty acid tails make the membrane more fluid
Why is Fe+ not able to move directly through the
membrane?
a. it is amphipathic
b. it is non-polar
c. it is too large
d. it carries a charge
e. it does not contain carbon - .....ANSWER... ✔✔ d. it
carries a charge
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A 0.9% NaCl solution is isotonic to red blood cells. If a
red blood cell is placed in 4% NaCl, what will occur?
a. cell lysis
b. crenation
c. turgor pressure
d. plasmolysis
e. nothing - .....ANSWER... ✔✔ b. crenation
what is crenation? - .....ANSWER... ✔✔ cell shrinkage
(osmosis may promote this)
what type of transport protein can move two or more
different molecules in opposite directions?
a. antiporter
b. uniporter
c. diporter
d. symporter
e. multiporter - .....ANSWER... ✔✔ a. antiporter
what is a antiporter? - .....ANSWER... ✔✔ they bind
two or more different types of ions or molecules and
transport them in opposite directions
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What is turgor pressure? - .....ANSWER... ✔✔ the
internal water pressure generated in plant cells as the
cell membrane presses on. the cell wall.
what are uniporters? - .....ANSWER... ✔✔ they bind a
single molecule or ion and transport it across the
membrane
what are symporters or co-transporters? - .....ANSWER...
✔✔ bind two or more different types of ions or
molecules and transport them in the same direction
The cell transports Ca2+ from the cytosol (low Ca2+
concentration) into the ER (high Ca2+ concentration).
Which statement about this process is INCORRECT?
a. calcium movement involves active transport
b. calcium movement requires an input of energy
c. calcium movement occurs by facilitated diffusion
d. calcium movement occurs through a transmembrane
protein - .....ANSWER... ✔✔ c. calcium movement
occurs by facilitated diffusion.
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What is facilitated diffusion? - .....ANSWER... ✔✔
diffusion across a membrane with the aid of transport
proteins
a form of passive transport (does not require energy)
moves down, with no energy.
what is active transport? - .....ANSWER... ✔✔ the
movement of ions or molecules against a concentration
gradient using energy from ATP.
from low concentration to high concentration. Not
energetically favourable
Primary active transport - .....ANSWER... ✔✔ uses
energy directly to transport a solute against a
concentration gradient
secondary active transport - .....ANSWER... ✔✔ uses
pre-existing gradient to drive the active transport of
another solute.
What is exocytosis? - .....ANSWER... ✔✔ a process in
which material inside the cell is packaged into vesicles
and excreted into the extracellular environment.
BIOL 1P91 MIDTERM EXAM QUESTIONS AND
ANSWERS 2025
All of the following statements about membrane fluidity
are true EXCEPT:
a. shorter fatty acid tails increase membrane fluidity
b. saturated fatty acid tails make the membrane more
fluid
c. membrane fluidity is affected by the presence of
double-bonds in the fatty acid tails
d. at high temperatures, cholesterol makes the
membrane less fluid - .....ANSWER... ✔✔ b. saturated
fatty acid tails make the membrane more fluid
Why is Fe+ not able to move directly through the
membrane?
a. it is amphipathic
b. it is non-polar
c. it is too large
d. it carries a charge
e. it does not contain carbon - .....ANSWER... ✔✔ d. it
carries a charge
,2|Page
A 0.9% NaCl solution is isotonic to red blood cells. If a
red blood cell is placed in 4% NaCl, what will occur?
a. cell lysis
b. crenation
c. turgor pressure
d. plasmolysis
e. nothing - .....ANSWER... ✔✔ b. crenation
what is crenation? - .....ANSWER... ✔✔ cell shrinkage
(osmosis may promote this)
what type of transport protein can move two or more
different molecules in opposite directions?
a. antiporter
b. uniporter
c. diporter
d. symporter
e. multiporter - .....ANSWER... ✔✔ a. antiporter
what is a antiporter? - .....ANSWER... ✔✔ they bind
two or more different types of ions or molecules and
transport them in opposite directions
,3|Page
What is turgor pressure? - .....ANSWER... ✔✔ the
internal water pressure generated in plant cells as the
cell membrane presses on. the cell wall.
what are uniporters? - .....ANSWER... ✔✔ they bind a
single molecule or ion and transport it across the
membrane
what are symporters or co-transporters? - .....ANSWER...
✔✔ bind two or more different types of ions or
molecules and transport them in the same direction
The cell transports Ca2+ from the cytosol (low Ca2+
concentration) into the ER (high Ca2+ concentration).
Which statement about this process is INCORRECT?
a. calcium movement involves active transport
b. calcium movement requires an input of energy
c. calcium movement occurs by facilitated diffusion
d. calcium movement occurs through a transmembrane
protein - .....ANSWER... ✔✔ c. calcium movement
occurs by facilitated diffusion.
, 4|Page
What is facilitated diffusion? - .....ANSWER... ✔✔
diffusion across a membrane with the aid of transport
proteins
a form of passive transport (does not require energy)
moves down, with no energy.
what is active transport? - .....ANSWER... ✔✔ the
movement of ions or molecules against a concentration
gradient using energy from ATP.
from low concentration to high concentration. Not
energetically favourable
Primary active transport - .....ANSWER... ✔✔ uses
energy directly to transport a solute against a
concentration gradient
secondary active transport - .....ANSWER... ✔✔ uses
pre-existing gradient to drive the active transport of
another solute.
What is exocytosis? - .....ANSWER... ✔✔ a process in
which material inside the cell is packaged into vesicles
and excreted into the extracellular environment.
