Biology 111 Exam 1 Questions with Correct
Answers
The slowest rate of diffusion of dye particles in water will occur at:
10 C
Which type of cell would you expect to burst when placed in a hypotonic solution?
red blood cell
Which of the following requires adenosine triphosphate?
active transport
Cells use exocytosis to:
release substances from the cell.
The diffusion of water molecules across a selectively permeable membrane is called:
osmosis.
Which of the following transport processes require(s) energy?
endocytosis
The bacterium Vibrio cholerae releases a toxin that blocks a channel protein in the
membranes of cells that line the intestine. This toxin prevents the movement of
positively charged sodium ions out of the intestine and into these cells. If the sodium
ions could not move into the cells, how would this affect the movement of water?
Water would leave the cells and enter the intestines by osmosis.
A cell is placed in a hypotonic solution. What will happen?
Water will move into the cell.
,A hormone circulating in the bloodstream would most likely bind to __________.
a receptor protein
The secretion of excess water via the contractive vacuole of a Paramecium cell is an
example of:
exocytosis.
The point at which a substance is evenly dispersed within a fluid __________.
is referred to as dynamic equilibrium and happens when net diffusion is zero
What happens when diffusion moves molecules across the plasma membrane?
The process is relatively slow and is driven by concentration gradients
ISO membranes are inside-out membrane vesicles used by researchers in membrane
studies. As a molecule diffuses into the vesicle, it will encounter the layers of the
membrane in the following order:
head-tail-tail-head.
The main lipids found in cell membranes are:
phospholipids.
Each substance needs a different type of transport to get into a cell. Pick the answer
choices that accurately match the type of transport needed to convey each of the
following substances into a cell.oxygen, water, sodium ions, potassium ions, bacteria
(Note that sodium ions are more concentrated outside cells than inside; potassium ions
are more concentrated inside cells than outside.)
simple diffusion, osmosis, facilitated diffusion, active transport, endocytosis
,Specialized cell junctions include all of the following EXCEPT:
phospholipases.
Which process accounts for the movement of solids into some animal cells?
phagocytosis
The concentration of sodium ions is lower in the cytoplasm of a heart muscle cell than it
is in the extracellular fluid. By what mechanism does the cell maintain this difference?
active transport
Which cell junctions function to make the connections between cells leakproof?
tight junctions
In osmosis, water diffuses from the side of the membrane with a higher concentration of
water to the side with a lower concentration of water. What determines the
concentration of water in a solution?
the amount of molecules other than water dissolved in the solution
Glucose is a six-carbon sugar that diffuses slowly through artificial phospholipid
bilayers. The cells lining the small intestine, however, rapidly move large quantities of
glucose from the glucose-rich food into their glucose-poor cytoplasm. Given this
information, which transport mechanism is most probably functioning in the intestinal
cells?
facilitated diffusion
Many metabolic poisons work by inhibiting ATP production. Which type of transport
would be most affected?
active transport
, In reference to diffusion, "passive" really means:
no energy required.
Which of the following processes does a cell use to take up molecules against their
concentration gradient?
both active transport and endocytosis
According to the fluid mosaic model of cell membranes, which of the following is a
TRUE statement about membrane phospholipids?
They form a viscous fluid through which proteins shift and flow.
Cystic fibrosis is a genetic disease that leads to the production of excessive, thick mucus
in the respiratory tract, causing frequent and serious respiratory infections. The defect
is due to the production of a faulty membrane protein for the transport of the chloride
ion. The protein exists in membranes, but it doesn't function normally.Based on this
scenario, what is occurring at the molecular level in a person with cystic fibrosis?
A channel protein is being adversely affected.
Osmosis is the diffusion of water molecules across selectively water-permeable
membranes. True or False?
True
When a drop of food coloring is placed in a glass of water, the spreading out of the
molecules of food dye is caused by __________.
the random movement of molecules
Facilitated diffusion requires __________.
a membrane transport protein and a concentration gradient
Answers
The slowest rate of diffusion of dye particles in water will occur at:
10 C
Which type of cell would you expect to burst when placed in a hypotonic solution?
red blood cell
Which of the following requires adenosine triphosphate?
active transport
Cells use exocytosis to:
release substances from the cell.
The diffusion of water molecules across a selectively permeable membrane is called:
osmosis.
Which of the following transport processes require(s) energy?
endocytosis
The bacterium Vibrio cholerae releases a toxin that blocks a channel protein in the
membranes of cells that line the intestine. This toxin prevents the movement of
positively charged sodium ions out of the intestine and into these cells. If the sodium
ions could not move into the cells, how would this affect the movement of water?
Water would leave the cells and enter the intestines by osmosis.
A cell is placed in a hypotonic solution. What will happen?
Water will move into the cell.
,A hormone circulating in the bloodstream would most likely bind to __________.
a receptor protein
The secretion of excess water via the contractive vacuole of a Paramecium cell is an
example of:
exocytosis.
The point at which a substance is evenly dispersed within a fluid __________.
is referred to as dynamic equilibrium and happens when net diffusion is zero
What happens when diffusion moves molecules across the plasma membrane?
The process is relatively slow and is driven by concentration gradients
ISO membranes are inside-out membrane vesicles used by researchers in membrane
studies. As a molecule diffuses into the vesicle, it will encounter the layers of the
membrane in the following order:
head-tail-tail-head.
The main lipids found in cell membranes are:
phospholipids.
Each substance needs a different type of transport to get into a cell. Pick the answer
choices that accurately match the type of transport needed to convey each of the
following substances into a cell.oxygen, water, sodium ions, potassium ions, bacteria
(Note that sodium ions are more concentrated outside cells than inside; potassium ions
are more concentrated inside cells than outside.)
simple diffusion, osmosis, facilitated diffusion, active transport, endocytosis
,Specialized cell junctions include all of the following EXCEPT:
phospholipases.
Which process accounts for the movement of solids into some animal cells?
phagocytosis
The concentration of sodium ions is lower in the cytoplasm of a heart muscle cell than it
is in the extracellular fluid. By what mechanism does the cell maintain this difference?
active transport
Which cell junctions function to make the connections between cells leakproof?
tight junctions
In osmosis, water diffuses from the side of the membrane with a higher concentration of
water to the side with a lower concentration of water. What determines the
concentration of water in a solution?
the amount of molecules other than water dissolved in the solution
Glucose is a six-carbon sugar that diffuses slowly through artificial phospholipid
bilayers. The cells lining the small intestine, however, rapidly move large quantities of
glucose from the glucose-rich food into their glucose-poor cytoplasm. Given this
information, which transport mechanism is most probably functioning in the intestinal
cells?
facilitated diffusion
Many metabolic poisons work by inhibiting ATP production. Which type of transport
would be most affected?
active transport
, In reference to diffusion, "passive" really means:
no energy required.
Which of the following processes does a cell use to take up molecules against their
concentration gradient?
both active transport and endocytosis
According to the fluid mosaic model of cell membranes, which of the following is a
TRUE statement about membrane phospholipids?
They form a viscous fluid through which proteins shift and flow.
Cystic fibrosis is a genetic disease that leads to the production of excessive, thick mucus
in the respiratory tract, causing frequent and serious respiratory infections. The defect
is due to the production of a faulty membrane protein for the transport of the chloride
ion. The protein exists in membranes, but it doesn't function normally.Based on this
scenario, what is occurring at the molecular level in a person with cystic fibrosis?
A channel protein is being adversely affected.
Osmosis is the diffusion of water molecules across selectively water-permeable
membranes. True or False?
True
When a drop of food coloring is placed in a glass of water, the spreading out of the
molecules of food dye is caused by __________.
the random movement of molecules
Facilitated diffusion requires __________.
a membrane transport protein and a concentration gradient
