BIO 2 GO!
3213a
Cellular Movement
Cells that have the ability to move generally have an advantage
over cells that cannot move.
Upon successful completion of this unit, you should be able to do the following:
1. List and explain the 3 types of movement found in cells.
2. Use the following words correctly:
Flagella
Cilia
Pseudopodia
Unicellular
Multicellular
Euglena
Paramecium
Amoeba
Cellular Movement
3.2.1.3a
Some living organisms consist of only 1 cell. They are the simplest form of
life. They can be plant or animal. However, even though they have only 1 cell, they
still perform all of the life functions, like cellular respiration. Organisms that
consist of only 1 cell are called unicellular.
Most unicellular organisms live in water. Some unicellular organisms simply
float along with water currents. Most unicellular organisms have the ability to
move. These organisms usually are moving toward food or away from danger. There
is a survival advantage in being able to move. This unit explains the movement of
these unicellular organisms.
There are 3 specialized
1.
2.
3.
structures that allow unicellular organisms to move:
flagella
cilia
pseudopodia
1. Flagella
Flagella are whip-like, or tail-like, structures that are attached to the cell
and move it. They act like a tail or whip and wave back and forth to move the
unicellular organism. Generally, the cell only has 1 flagella. It is not a very
efficient way to travel. The unicellular organism, euglena, uses a flagella to move
toward light.
2. Cilia
Cilia are hair-like structures that often surround a cell. They work together
much like oars or paddles on a boat. They are more efficient than flagella
movement. Parameciums are unicellular organisms that use cilia to move toward
food.
3. Pseudopodia
Pseudopodia means “false foot”. A pseudopod is a blob-like extension of the cell
membrane. It occurs when the cell tries to move in a direction. When this happens
a section of the cell membrane extends in the direction the cell wants to move
and the rest of the cell follows. In order to move, the organism has to change its
shape. It is usually slower than flagella movement.
REMEMBER THIS !!!
Flagella, cilia, and pseudopodia are the means by which unicellular
organisms move.
Interesting Scientific Fact: An amoeba is a unicellular organism that is so small
that it is barely visible. When horror films were popular, the amoeba became
popular as “The Blob”. The horror films made the amoeba large enough to eat a
building or town. The films show the amoeba moving by pseudopodia.
Question 1. What is the difference between a unicellular organism and a
multicellular organism?
Question 2. List and explain the 3 specialized structures for cell movement.
Summary
Cellular Movement
3.2.1.3a
There are three main structures that can be used to help a single-celled
organism move about. They are called flagella, cilia, and pseudopodia.
A euglena is an example of a unicellular organism that has a flagellum. The
flagellum is a single, long tail-like structure. It can be waved in a circular motion
to create movement. A euglena must be able to move toward the light to be able to
make its food.
A paramecium is an example of a unicellular organism that has cilia. Cilia are
much shorter than flagella. There are many of them surrounding a paramecium.
Paramecia move their cilia together to create a wave of motion that helps them
move. Paramecia must move in order to find food or to avoid predators.
An amoeba is an example of a unicellular organism that has pseudopodia.
Pseudopodia are extensions of the cytoplasm that allow the cell membrane to
change shape and the amoeba to move. Amoeba cannot move as quickly as euglena
or paramecium, but they can move. This helps them obtain food and avoid
predators.
Cellular Movement
Test Yourself
Matching
_____1. paramecium
_____ 2. euglena
_____ 3. amoeba
_____ 4. flagellum
_____ 5. cilia
_____ 6. pseudopodia
a.
b.
c.
d.
e.
f.
has flagellum
a long, single, tail-like structure
has cilia
many short hairs that move together
has pseudopodia
extensions of cytoplasm
True or False
_____ 1.
_____ 2.
_____ 3.
_____ 4.
_____ 5.
Unicellular organisms cannot move.
Unicellular organisms have special structures to help them move.
A flagellum is a long, tail-like whip that can cause movement.
A flagellum is an extension of the cytoplasm that allows movement.
A flagellum is one of many short hairs that work together to create
movement.
_____ 6. A cilium is an extension of the cytoplasm that allows movement.
_____ 7. A cilium is one of many short hairs that work together to create
movement.
_____ 8. A pseudopodium is an extension of the cytoplasm that allows movement.
_____ 9. A pseudopodium is one of many short hairs that work together to create
movement.
_____ 10. A euglena has a pseudopodium for movement.
Fill in the Blank
cilia
euglena
flagellum
amoeba
pseudopodia
paramecium
1. The _________________ is an example of an organism with
__________________, extensions of the cytoplasm that allow movement.
2. A _____________________ has hundreds of _______________, short hairs
that surround its cell membrane, for movement.
3. A _______________________ has a tail-like structure, called a
________________, for movement.
Answer the Following
1. What is a flagellum? Name an organism that has one.
2. What are cilia? Name an organism that has them.
3. What are pseudopodia? Name an organism that has them.
Cellular Movement
Test Yourself
Question 1. What is the difference between a unicellular organism and a
multicellular organism?
Question 2. List and explain the 3 specialized structures for cell movement.