Cells Are Us

Cheryl L. Trammell             Delano Elementary School
                               3937 W. Wilcox Street
                               Chicago IL 60624
                               (312) 534-6620

Objectives:

(These objectives are suitable for K-3 grade levels.)

The main objectives of this mini-teach are to show that the cell is the basic 
unit of life; that cells divide slowly to become mass of cells (mitosis); and
that there is a gradual loss of cells throughout life.  

Materials Needed:

Cell Observation(s)              Cell Loss Observation(s)
"Cells Are Us" song                     (memory)
paper                            pencils
pencils                          paper
microscope                       shopping bag
slides                           various items to be used
slide covers                     for observation
iodine                           index cards
eye dropper                      envelopes
cotton swabs                     markers
water                            "Hocus Focus" picture
long balloons                    
string
marbles

Strategy:

Cell Observation
1.  Distribute "Cells Are Us" song to class.
    Have class sing song which explains about mitosis.
2.  Ask students to draw a dot on paper.  Tell class: "This was you -- billions 
    of cells ago."
3.  Distribute microscopes.  Have students:
    a.  Gently scrape inside of cheek with cotton swab;
    b.  Stir end of cotton swab in drop of water on a slide;
    c.  Add a drop of iodine solution to color cells;
    d.  Look at slide under microscope to observe skin cells.
4.  Give each student two long balloons and string.  Have students blow up one 
    balloon and twist the ends in opposite directions to give an idea of what 
    the first egg cell division looks like.  They can also tie a string in the 
    opposite direction (if the balloon doesn't burst) to show a model of the 
    second division.  Explain that the cells go on dividing.
5.  Demonstrate how cells keep getting smaller and smaller, and become crowded 
    for room.  Show how they begin to arrange themselves into a ball, or sphere, 
    with an open space in the middle because of their rounded shape.
    a. Take some marbles and push them together.
    b. Demonstrate how the marbles pack tightly if you use just a few.
    c. Add more marbles and you will find that they tend to arrange themselves 
       around an opening left in the center.
    d. Explain how this process goes on and on and on.

Cell Loss Observation (memory)
1.  Distribute "Hocus-Focus" picture to the class.  Have students write down at 
    least six differences that they see between panels.
2.  Put 18-20 various items into shopping bag.  Have the students observe as you 
    name the items as you remove it from the bag.  Have volunteers orally recall      
    as many of the items as they can.  The volunteer with the most correct 
    responses may select one of the items as a prize.  
3.  Draw/write duplicates of various pictures and symbols on index cards.  
    Place in two separate envelopes.  Have students observe cards for one 
    minute then write down the names of the items in the envelope. 
4.  Have students with color-coded cards work in pairs.  Mix up and turn over
    the cards in both envelopes.  Have students try to find and match like 
    pairs.
  
Performance Assessment:

At the conclusion of the mini-teach, students will be able to answer the 
following questions: 
1.  What are cells?
2.  Can you explain mitosis?
3.  Why is cell division important?
4.  What effect does aging have on mitosis?
 
Conclusions:

Students will understand that a cell is a tiny unit of life; the smallest 
"building blocks", from which all living things are made and that cell 
production slows as we age.