Microscopic Life

1
Microscopic Life

• Investigation Three

2
Elodea

• Elodea is a aquatic plant.
• Turn to page 15 in your packet. Read directions.
• Create a wet mount of the elodea leaf.
• One person will bring a slide, dropper,
  coverslip, and forceps to the back counter.
• Place materials on a paper towel.
• Identify your pond and place half of an elodea
  leaf on your slide using the forceps. Add 2-3
  drops of pond water and cover slide with a
  coverslip. Dry, wash and secure all materials.
  Return to your table. Complete Part 1 and 2.

3
Elodea Discussion Questions

• 1. What do you see when you look at the Elodea?
• 2. When you focus up and down through the leaf
  sample, what did you notice?
• 3. Are the rectangles flat, like designs drawn on
  the surface of the leaf, or are they three
  dimensional?
• 4. Are the boxes empty?
• 5. How many layers of these bricks do you see?

4
Cell Size

• 6. What are the boxes or bricks that you see on
  the Elodea leaf?
• 7. Are all of the cells on the Elodea leaf the
  same size?
• 8. How many layers of cells are there in an
  Elodea leaf?
• 9. Are the large cells on the top of the leaf or
  the bottom?
• 10. How big are the Elodea cells?
• 11. Did you notice anything moving inside any of
  the cells? What did it look like?

5
ELODEA NOTES

• Cells are the basic unit of life. The boxes or
  bricks that you see on the Elodea leaf are cells.
  Cells are the units from which the Elodea leaf
  is made.
• Cells are filled with a fluid called cytoplasm.
  Cytoplasm can sometimes be seen moving inside the
  cells of living plants.
• The green balls moving in the cytoplasm are
  chloroplasts. They give green plants their color.

6
Part 2 and 3

• What else was in the elodea slide? Were they
  alive?
• What makes you think they are/are not alive?
  Whats your evidence?
• What do you think they are?
• Complete Part 2 and 3 on p. 15.
• Make sure you write down and draw exactly what
  you see in the field of view.
• Discuss observations with table.

7
Wet Mounts of Paramecium

• View Lab Techniques/CD ROM
• Bring slide, dropper, cotton ball, and coverslip
  to the back sink. Work on top of the paper
  towels, take one drop of pond water and add it to
  the slide. Pull a few pieces of cotton filament
  from the cotton ball and place it onto of the
  pond water. Put coverslip on top and return to
  your table.

8
Paramecium single celled

• What movements did you observe?
• What did you see on the inside of the paramecium?
• What did you see on the outside of the
  paramecium?
• How big was it at 100x? 400X?
• Are they living or nonliving? What is your
  evidence?
• Could you see if it was doing all of the things
  you have listed in your definition of a living
  organism?
• Did you see it eat or use energy? Give waste?
  Reproduce? Etc
• What might we do to see some of these activities?

9
Elodea vs Paramecia

• What did the microscopic structure of the elodea
  look like?
• What did the microscopic structure of the
  paramecium look like? Did it look like it was
  made out of cells?
• Do the things inside of the paramecium look like
  the things inside the elodea cells?
• What were some similarities and differences?

10
Paramecium vs Elodea Facts

• Paramecia are single celled organisms.
• Just like the individual green bricks in the
  Elodea are individual cells, each paramecium is
  an individual cell.
• The Elodea plant is an organism. It is made of
  many cells and it is a multicellular organism.
• The paramecium is an organism. It however, has
  one cell, single-celled organism.
• Paramecia and other single celled organisms
  belong to the kingdom of life called Protista.
  Some common protist are ameba, euglena, and
  flagellates.

11

• The Elodea plant and the individual paramecium
  cell are both organisms because they can live on
  their own.
• The individual Elodea cell, although it shows
  signs of life, is not an organism.
• Evidence The Elodea cells stay in one place
  paramecium move around. Elodea cells are stuck
  together paramecium are alone.
• Elodea cells are part of a bigger organism
  paramecium are not.
• An organism is always free-living. It is not a
  part of a larger living organism.

12
Characteristics of Cells

• Cells are alive.
• Life happens in cells and only in cells.
• Some cells live alone while others live with
  millions of others, like the Elodea leaf cells.
• Not all cells are organisms, because not all
  cells are able to live independently.
• An organism, single or multi-celled, can do all
  characteristics of life.