Osmosis and Organisms Practice
1) Use the four types of transport below to answer the following questions:
I.
Diffusion
II.
Osmosis
III.
Facilitated Diffusion
IV.
Active transport
___Which type of transport requires ATP?
___Which type of transport is considered “passive”?
___Which type of transport moves molecules with the concentration gradient?
___Which type of transport moves only water molecules?
The two diagrams to the right show a protein channel
moving a large molecule across the lipid bilayer membrane.
A
2) What is the difference between the two pictures?
3) Which types of transport are seen in A and in B?
B
4) In muscle cells, potassium ions are “pumped” from a region of low concentration to high
concentration. This mechanism allows your muscles to function properly. This type of cell
transport is known as
a. Diffusion
b. Active transport
5) Draw an arrow to show which
c. Osmosis
way water will move:
d. Passive transport
6) Identify if the following situations would cause a cell to shrink
or to swell
a. Water was 90% inside the cell and 95% outside the cell
b. Protein was 30% inside the cell and 35% outside the cell
c. Water was 95% inside the cell and 90% outside the cell
d. Salt is 15% inside the cell and 5% outside the cell
e. Water and protein was equal inside and outside the
cell
7) In the diagram to the right, the same type of molecule is shown in area A and area B. After
passage of time, molecules from A move to B. What type of transport does this demonstrate?
8) If molecules moved from B to A, what type of transport?
9) Freshwater single-celled organisms live in an environment with low concentrations of salt. Draw
a picture to describe what would happen to a single-celled organism if it was moved from it’s
native habitat to a saltwater environment. Be sure to draw and label a diagram that shows the
relative concentrations of salt and an arrow to show how water would move
The diagram to the right shows a cell that was removed from a saltwater
environment and placed in a freshwater environment. Inside the cell, the
concentration of water is 4% while outside it is 90%.
4%
water
10) Predict what type of transport is about to occur, remembering that
salt water cannot move across the membrane.
90%
water
11) Draw an arrow to show how water will move. Identify high and low concentrations on the
diagram. What will happen to the cell – will it swell or shrink? Explain how you know.
12) A student prepared a microscope slide by placing a piece of red onion on the slide and adding a
few drops of distilled water to the slide. What would happen to the cell if after adding distilled
water, the student added salt water?
a)
b)
c)
d)
It will shrink because water is leaving by osmosis.
It will swell because water is entering by osmosis.
It will swell because water is entering by diffusion.
It will stay the same.
13) Jellyfish have a permeable membrane and that accomplish homeostasis in the saltwater
environment they live in. If you placed a jelly fish in freshwater, how would this affect the
jellyfish cells?
a) It would gain water from the environment
b) It would lose water to the environment
c) It will gain nutrients from the environment
d) It would lose salt into the water
14) Freshwater protozoans, such as Paramecia, must constantly pump water out to keep from
bursting. What does this tell you about the concentration of particles inside a Paramecium
compared to the concentration of particles of its environment?
15) Which fluid was most likely added to the cell’s surroundings?
A. Salt solution
C. Iodine solution
B. Tap water
D. Distilled water
Explain your answer choice above:
16) Cabomba is a plant that lives in freshwater. Describe what would happen to the cells of a
piece of Cabomba if it were placed in salt water. Justify your answer with the following
terms: osmosis, high concentration, low concentration, water, salt, swell or shrink,
concentration gradient.
Notes - Osmosis and Organisms
1) If an organism lives in a freshwater environment, the internal environment
of that organism’s cells will have a high water concentration and a low salt
concentration.
Example: The cells of a bluegill fresh water fish will have a high water
concentration and low salt concentration.
2) If an organism lives in a saltwater environment, the internal environment of
that organism’s cells will have a low water concentration and high salt
concentration.
Example: starfish that live in the ocean are made up of cells that are high
in salt, low in water.
3) Moving an organism from freshwater to saltwater will cause water to move
out of its cells. Its cells will shrink.
4) Moving an organism from saltwater to freshwater will cause water to move
into the cells. Its cells will swell.
5) If given a percentage concentration of a solute
(protein, salt, sugar, etc.), it must be converted
into water concentration so you can determine
how water will move.
40% sugar
Guided Practice
1) While cleaning a saltwater aquarium, students placed the aquarium plants in a container of
distilled water. What effect will this have on the plants? (Draw a picture)
50% sugar
2) A cell is taken from an environment that has a high salt concentration and is placed into an
environment that does not contain any salt. What effect will the change in environment have on
the cell?
3) Predict how water will move by drawing an arrow. Assume that particles cannot move across
the membrane.
Kingdom name
picture
producerOR
consumer
unicellularOR
multicellular?
sexualOR asexual
cell wall OR no
cell wall?
eukaryoticOR
prokaryotic?
What are the two types of
cells?
Which cell type has a
nucleus?
Plantae
Animalia
Fungi
Bacteria (Monera)
Protista
Which cell type has
membrane-bound
organelles?
Which cell type is LARGER?
Circular or Linear DNA?