CECsci.182


TITLE:    PROTOZOANS

AUTHOR:   JIM L. TORGERSON, NORTH SEVIER MIDDLE
          SCHOOL, SALINA, UTAH

GRADE LEVEL:   Appropriate for  grades 6-8.

OVERVIEW:  The students will be able to describe
one-celled protozoans (i.e. amoeba, paramecium,
euglena, etc.)

PURPOSE:  By gaining an understanding of protozoans,
students will have the knowledge to deal with
one-celled organisms, their advantages and
disadvantages.

OBJECTIVE(s):  STUDENTS WILL BE ABLE TO:
1.  Tell what a protozoan is.
2.  Draw  and label a protozoan.
3.  Explain how different protozoans can affect
    them.
4.  Understand protozoans relationships to their
    environment.

RESOURCES/MATERIALS:
     You will need to start a pond water culture.  The
pond water culture should be started 7 to 10 days
before its use.  Alfalfa or dry grass in a jar of pond
water should be kept in a warm place with subdued light
for protists to grow in numbers.  The protists are more
likely to be found at the bottom of the culture.  To
get them out of the jar use a pipett or straw.  If you
use a straw, place one finger over the end of the straw
and lower the other end into the culture to the level
you want to sample.  Lift your finger just long enough
to obtain the sample and then lift from the jar.  You
can purchase pure cultures from a science supply house.
But, the students seem to have more fun obtaining and
growing their own cultures.

Resources:
LIFE SCIENCE TEXT BOOK, BIOLOGY TEXT BOOKS,
ENCYCLOPEDIA, ANY OTHER RESOURCES THAT RELATE TO
PROTOZOANS THAT ARE AVAILABLE.

You will need the following materials:
1.  microscope (and knowledge of it's use)
2.  pond water culture
3.  straw or pipett
4.  microscope slide and coverslips
5.  paper and pencil for notes.

    Make sure students have had experience labeling
    parts of protozoans before starting this
    activity.

BACKGROUND INFORMATION:
     Protists are one-celled organisms.  Protists can
be classified into four groups by the way they move:
Sarcodines move by pseudopodia (false feet), ciliates
move by cilia, flagellates move by flagella, and
sporozoans which have no method of movement and most
live as parasites.

ACTIVITIES AND PROCEDURES:
     Have students put a drop of pond water on a
microscope slide.  Cover the drop with a cover slip.
Put the slide on the microscope stage.  Focus the
microscope, using the techniques discussed in a
previous lesson.  Have students draw  on a piece of
paper what microorganisms they are able to see.  Have
students identify the microorganisms they are drawing.
Have students use reference sources to identify and
label the microorganisms being viewed.   After the lab,
discuss the advantages and disadvantages of protozoans
(i.e., protozoan diseases, etc.)  This will probably be
done in another class period.  Also discuss how
protozoans affect their environment.

TYING IT ALL TOGETHER:

Cross-Curriculum Ideas:
Math:  Suppose that a protozoan reproduces every thirty
minutes.  You start out with one.  Thirty minutes later
you have two, one hour later you have four, etc.
Figure out how may protozoans would be available twelve
hours later if none of them died.

English:  Scramble the letters of the main vocabulary
words within the protozoan chapter.  Have the students
unscramble them.

Art:  Draw and color protozoans as you would see them
in their natural surroundings.

Health:  Protozoan disease reports.