NEW
Font size
WorksheetsCell Membrane and Homeostasis
Total questions: 24
Worksheet time: 25mins
The diagram below represents a cell in water. Explain why more water is moving out of the cell than into the cell.
The concentration of solute in the cell is higher than it is outside the cell.
The concentration of water outside the cell is too great.
The concentration of solute outside the cell is higher than it is inside the cell.
The concentration of water inside the cell is greater than it is outside the cell.
What types of materials are expelled from cells during exocytosis?
large molecules such as hormones
positive and negative ions
small molecules such as carbon dioxide
water and glycerol
Algal cells are placed in an hypotonic solution. What happens to the cells?
They will begin to swell.
They will burst.
They will stay the same.
They will shrink.
How is the plasma membrane of a cell organized?
one layer of phospholipids, through which proteins freely move
one layer of phospholipids, which are laid out end-to-end, with a hydrophobic tail touching a hydrophilic head
two layers of phospholipids, each of which has its hydrophilic side turned inward
two layers of phospholipids, with their polar hydrophilic heads facing away from each other
The process of the plasma membrane pumping excess sodium (a large molecule/energy is needed) out of a cell into an environment where there is a lower concentration of sodium is called _________.
diffusion.
osmosis.
active transport.
coupled transport.
What characteristic of the plasma membrane is illustrated in this drawing?
selective permeability
active transport
fluid mosaic construction
impermeability to water
A plant cell is placed in a hypotonic solution. What will happen to the plant cell?
It will swell.
It will shrink.
It will stay the same.
It will wilt.
What is a major difference between facilitated diffusion and active transport?
Active transport moves substances against the concentration gradient.
Active transport uses proteins in the process.
Facilitated diffusion moves molecules through the plasma membrane.
Facilitated diffusion requires large amounts of energy.
Which of the following is an example of passive transport?
endocytosis
exocytosis
facilitated diffusion
Na+/K+ ATPase pump
At what point in the process of diffusion is dynamic equilibrium reached?
when the movement of the molecules
when the molecules are mixed and stop moving
when the rate of change in the solution slows by one half
when there is continuous movement but no change in size of cell
Which of the following substances would have the most trouble crossing a biological membrane by diffusing through the lipid bilayer?
O2
CO2
Na+
a small, nonpolar molecule such as butane (C4H10)
Diffusion does not require the cell to use energy. Therefore, diffusion is considered a type of
exocytosis
passive transport
active transport
endocytosis
Osmosis can be defined as
the diffusion of water.
the diffusion of nonpolar molecules.
active transport.
the diffusion of a solute.
Some protozoans have special organelles called contractile vacuoles that continually eliminate excess water from the cell. The presence of these organelles tells you that the environment
is isotonic to the protozoan.
is hypotonic to the protozoan.
contains a higher concentration of solutes than the protozoan.
is hypertonic to the protozoan.
A cell that has neither a net gain of water nor net loss of water when it is immersed in a solution must be
isotonic to its environment
hypertonic to its environment
hypotonic to its environment
metabolically inactive
In a hypotonic solution, an animal cell will
swell and maybe burst.
will lose turgor.
neither gain nor lose water.
shrivel.
If placed in tap water, an animal cell will undergo lysis (burst), whereas a plant cell will not. What accounts for this difference?
the expulsion of water by the plant cell's central vacuole
the relative impermeability of the plant cell wall to water
the fact that plant cells are isotonic to tap water
the relative strength of the plant cell wall
You are adrift in the Atlantic Ocean and, being thirsty, drink the surrounding seawater. As a result,
you quench your thirst
your cells become turgid
you dehydrate yourself
your cells lyse (burst) from excessive water intake
Facilitated diffusion across a biological membrane requires ________ and moves a substance ________ its concentration gradient.
energy and transport proteins; down
transport proteins; down
energy and transport proteins; against
transport proteins; against
Which of the following processes can move a solute against its concentration gradient?
osmosis
passive transport
facilitated diffusion
active transport
A group of single cell organisms collected from the ocean was brought into the lab for examination. The lab assistant was concerned that the water had become full of toxic waste products and so added clean water to the culture. All of the organisms died, and when she looked at them under the microscope, all she could see were bits and pieces of them scattered throughout the water. What likely happened?
She added water that was hypotonic to the organisms, and they ruptured.
She added sea water to which she had added too much salt, and they ruptured.
She added isotonic water to the organisms, causing too much water to move in and out of the organism, and they ruptured.
She added too little salt to the sea water she added, and the organisms all lost too much water and shriveled up.
Which figure depicts an animal cell placed in a hypotonic solution?
Cell A
Cell B
Cell C
Cell D
Which of the following most accurately describes selective permeability?
An input of energy is required for transport.
Lipid-soluble molecules pass through a membrane.
There must be a concentration gradient for molecules to pass through a membrane.
Only certain molecules can cross a cell membrane.
Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly?
Water
an amino acid
glucose
K+
