Bio 253- Chapter 3 UPDATED ACTUAL
Exam Questions and CORRECT Answers
What are the functions of the cell membrane? - CORRECT ANSWER - -it is the site of
signal transduction
-it is a selectively permeable barrier
Within the cytoplasm, what is the clear liquid in which organelles are suspended? - CORRECT
ANSWER - cytosol- the question asks for the clear liquid found in the cytoplasm, which is
called cytosol. Recall that cytoplasm is composed of cytosol, organelles, and the cytoskeleton
What is the term used for membranous sacs that store or transport substances within a cell or
between cells? - CORRECT ANSWER - vesicle
Membranous sacs containing substances that were produced in the cell, such as neurotransmitters
or hormones, are called - CORRECT ANSWER - vesicles
The process that occurs due to the random movement of atoms, molecules, or ions in air or
liquid, from areas of higher concentration to areas of lower concentration, is known as -
CORRECT ANSWER - diffusion
A substance moving from an area of high concentration to an area in which it has a low
concentration is moving ______ the concentration gradient. - CORRECT ANSWER -
down
What are microvilli? - CORRECT ANSWER - Tiny extensions of the cell membrane that
absorb substances.
Diffusional ______ occurs when the concentration of a given substance becomes uniform
throughout a solution and there is no further net movement of molecules throughout the solution.
- CORRECT ANSWER - equilibrium
, The nucleus contains ______, which directs all cell activities. - CORRECT ANSWER -
DNA
Diffusion of a substance across a membrane can happen only if the membrane is ______ to that
substance and a concentration gradient ______ across the membrane - CORRECT
ANSWER - permeable; exists
Which of the following would increase the diffusion rate? - CORRECT ANSWER - higher
temperature
The random movement of atoms, molecules, or ions in air or liquid, from areas of higher
concentration to areas of lower concentration, is called simple - CORRECT ANSWER -
diffusion
Ions that use specific protein channels in the membrane use a process called ______ to move
down their concentration gradient across the plasma membrane. - CORRECT ANSWER -
facilitated diffusion- while some ions are actively transported, the questions stated "down their
concentration gradient", which means passive transport
When molecules move down a concentration gradient, it means that there is a net movement of
particles from a region of lower concentration to a region of higher concentration (true or false) -
CORRECT ANSWER - false- molecules move down a concentration gradient when they
move from a region of higher concentration to a region of lower concentration.
Both simple diffusion and facilitated diffusion are ______ transport mechanisms that move
molecules ______ a concentration gradient. - CORRECT ANSWER - passive; down-
simple diffusion always goes down a gradient, like the passive rolling of a ball down a hill;
simple and facilitate diffusion are both passive processes
Osmosis is the diffusion of ______ through a selectively permeable membrane. - CORRECT
ANSWER - water
Exam Questions and CORRECT Answers
What are the functions of the cell membrane? - CORRECT ANSWER - -it is the site of
signal transduction
-it is a selectively permeable barrier
Within the cytoplasm, what is the clear liquid in which organelles are suspended? - CORRECT
ANSWER - cytosol- the question asks for the clear liquid found in the cytoplasm, which is
called cytosol. Recall that cytoplasm is composed of cytosol, organelles, and the cytoskeleton
What is the term used for membranous sacs that store or transport substances within a cell or
between cells? - CORRECT ANSWER - vesicle
Membranous sacs containing substances that were produced in the cell, such as neurotransmitters
or hormones, are called - CORRECT ANSWER - vesicles
The process that occurs due to the random movement of atoms, molecules, or ions in air or
liquid, from areas of higher concentration to areas of lower concentration, is known as -
CORRECT ANSWER - diffusion
A substance moving from an area of high concentration to an area in which it has a low
concentration is moving ______ the concentration gradient. - CORRECT ANSWER -
down
What are microvilli? - CORRECT ANSWER - Tiny extensions of the cell membrane that
absorb substances.
Diffusional ______ occurs when the concentration of a given substance becomes uniform
throughout a solution and there is no further net movement of molecules throughout the solution.
- CORRECT ANSWER - equilibrium
, The nucleus contains ______, which directs all cell activities. - CORRECT ANSWER -
DNA
Diffusion of a substance across a membrane can happen only if the membrane is ______ to that
substance and a concentration gradient ______ across the membrane - CORRECT
ANSWER - permeable; exists
Which of the following would increase the diffusion rate? - CORRECT ANSWER - higher
temperature
The random movement of atoms, molecules, or ions in air or liquid, from areas of higher
concentration to areas of lower concentration, is called simple - CORRECT ANSWER -
diffusion
Ions that use specific protein channels in the membrane use a process called ______ to move
down their concentration gradient across the plasma membrane. - CORRECT ANSWER -
facilitated diffusion- while some ions are actively transported, the questions stated "down their
concentration gradient", which means passive transport
When molecules move down a concentration gradient, it means that there is a net movement of
particles from a region of lower concentration to a region of higher concentration (true or false) -
CORRECT ANSWER - false- molecules move down a concentration gradient when they
move from a region of higher concentration to a region of lower concentration.
Both simple diffusion and facilitated diffusion are ______ transport mechanisms that move
molecules ______ a concentration gradient. - CORRECT ANSWER - passive; down-
simple diffusion always goes down a gradient, like the passive rolling of a ball down a hill;
simple and facilitate diffusion are both passive processes
Osmosis is the diffusion of ______ through a selectively permeable membrane. - CORRECT
ANSWER - water
