1. Investigation 3: Microscopic Life

2. At the end of Investigation 3 you will be able to:
Examine the structures of unicellular and multicellular organisms using a microscope.
Compare and contrast Elodea cells and unicellular organisms.
Describe the difference between living cells that are organisms and living cells that are not organisms.

3. Investigation 3 - Part 1 Discovering Cells

4. In the Beginning
In 100 AD, Romans began experimenting with glass as a magnifier.
First hand held lenses were about 6x -10x and were often called “flea glasses”
In 1590, two spectacle makers mad the first compound microscope
Galileo was intrigued and worked to make the invention better including telescopes
Anthony Leeuwenhoek ( ) improved the microscope so much that elements in blood and water were seen. He is called the "Father of Microscopy".

5. Timeline Continued
Robert Hooke, an Englishman (who is sometimes called the “English Father of Microscopy”) studied cork and dubbed the name cells for the little rooms in the cork.
In 1833, Robert Brown found that all plants had a nucleus
By 1838, the cell theory was created stating that cells are the “elementary particles of organisms.”

6. Finally Cells are said to live double lives in organisms
An individual life of their own
An incidental life that is part of a larger organism
Five kingdoms of life organize life into 5 categories
New information and species are being discovered daily

8. Today…
we will use microscopes to look at living materials to see what we can learn. We will start by looking at the leaves of an aquatic plant called Elodea.

9. ELODEA- LAB NOTEBOOK PAGE 15
Prepare a wet mount of a half of an Elodea leaf using the water from the container and complete part 1.

10. What do you see when you look at the Elodea?
When you focus up and down through the leaf sample, what did you notice?
Are the rectangles flat, like designs drawn on the surface of the leaf, or are they three-dimensional?
Students should see two layers, one of large squares and one of small squares that appear 3 dimensional like bricks or boxes.
Are the boxes empty?
How many layers of these bricks do you see?

11. Cells
The boxes that you see in the Elodea leaf are cells. Cells make up the leaf and they are too small to be seen with the naked eye, but they can be seen clearly with the microscope.

12. COMPLETE PART 2 ON PAGE 15
Look at page 11 in your lab notebook if you are having trouble estimating the cell size.
Draw only what you see in the field of view and use as much detail as possible.
It is okay to draw a representative sample of the cells as long as the size is proportionate to the field of view.

13. How big are the Elodea cells?
The larger ones are about 0.1mm.
The smaller ones are about 0.05mm.

14. Cytoplasmic Streaming
Did you notice anything moving inside any of the cells?
What did it look like?
Cells are filled with a fluid called cytoplasm.
Cytoplasm can sometimes be seen moving inside of living plants.

15. Investigation 3 – Part2 Paramecia

16. PARAMECIUM WET MOUNT
Lab techniques video Use only a few wisps of cotton. Paramecia tend to settle at the bottom of the container, so that is where you should obtain your sample.

17. Discussion Questions What movements did you observe?
What did you see on the inside of the paramecium?
What did you see on the outside of the paramecia?
How big was it at 100X? At 400X?
Are they living or non-living? What is your evidence?
Could you see it eat? Eliminate waste? Reproduce?
Students may have observed blobs, bubbles or dark areas inside the paramecium. They may also describe a grove, ‘skin’ little ‘legs’ or hairs. The paramecium is less than .5mm

18. COMPARING PARAMECIA AND ELODEA
What did the microscopic structure of the Elodea leaf 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 of the Elodea cells?

20. Paramecia are not made of cells, because each paramecium itself is a single cell. Just like the individual green “bricks” in the elodea are individual cells, each paramecium is an individual cell.

21. The Elodea plant is an organism. Elodea is made of many cells
The Elodea plant is an organism. Elodea is made of many cells. Elodea is a multicellular organism. The paramecium is an organism. The paramecium is, however, just one cell. Paramecium are single-celled organisms. How are Elodea cells and paramecium cells different? Discuss this question for a few minutes.

22. ORGANISM
Remember, our definition of an organism is any living thing that is free-living, that is, it is not a part of another organism.

23. Can a single living cell be an organism?
Can a single living cell not be an organism?
Is an Elodea leaf cell an organism?
Is a Paramecium cell an organism?
YES
YES NO
YES

24. Cells are alive. Life happens in cells and only in cells
Cells are alive. Life happens in cells and only in cells. Cells are the fundamental units of life. Some cells, like the paramecium live alone. Some cells, like the Elodea leaf cells, live with millions of others. Both are alive, and both do all of the things that we recognize as characteristics of life.

25. Paramecia are single-celled organisms in a kingdom of life called Protista. In Greek, proto means early and protist means the very first. So single-celled organisms like paramecia are members of the kingdom of life that includes organisms that are similar to some of the very first life-forms on Earth.

26. KINGDOM PROTISTA
Bear in mind, protists are not animals. Animals are always multicellular. Protista is a separate kingdom whose members are mostly single-celled.

27. FEEDING THE PARAMECIA LAB NOTEBOOK PAGE 17
We will feed them with Congo red-dyed yeast. The Congo red makes it easier to see the yeast and it is an acid indicator.
Watch what happens when acid interacts with Congo red-dyed yeast.
Place a petri dish with a few mL of water on the projector. Add a few drops of Congo red-dyed yeast and then add a few drops of vinegar as the acid. The Congo red should turn blue when an acid is present.

28. COMPLETE PAGE 17 IN YOUR LAB NOTEBOOK
How do you think the paramecia move?
How do they get the yeast into their bodies?
Do the paramecia have mouths?
How do the paramecia get rid of waste products?
What keeps their insides from spilling out?
What does the yeast inside a paramecium look like?

29. HOMEWORK
Please complete the response sheet on page 19 of your lab notebook.
Please read The Lowly Paramecium on pages of your resource book.
Respond to questions, plus one, and write a poem. (see next slide)

30. Write a Paramecium Poem

31. Investigation 3 - Part 3 Microworlds

32. More Microorganisms
Today we are going to look at a couple different types of microorganisms. Pay special attention to how they are similar to and different from the paramecia and each other.

33. Meet Mr. Amoeba, Miss Euglena, and Dr. Flagellate

34. We have had time to look at a number of different organisms that live in water. They are similar in some ways and different in some ways.
In your journal, draw and complete a triple Venn diagram to compare and contrast our organism samples.

35. Investigation 3 - Part 3 Microworlds Breakpoint

36. MINIPONDS
Just like any pond, your miniponds can be divided into different regions. Different regions of the pond might be used by different kinds of organisms. What regions might you sample?
Please avoid getting mud and dirt on the slide. It will prevent the cover slip from sitting flat on the sample.

37. MINIPOND SAFARI
What is a safari? We will go trekking through the various regions of the pond, using the microscope as our means of transportation.
An organized trip into wild country to look for animals
and other interesting things.

38. Philodinia Stentor ORGANISMS YOU MAY SEE
Protists that students may find in their minipond. These images and quicktime videos of microorganisms can be found at
Philodinia
Stentor

39. Daphnia Tardigrade ORGANISMS YOU MAY SEE
Organisms that students may find in their minipond. Both are multicellular animals. Students often think these are unicellular because they are microscope. These images and quicktime videos of microorganisms can be found at
Daphnia
Tardigrade

40. COMPLETE PAGE 25 IN YOUR LAB NOTEBOOK PLEASE USE THE MICROORGANISM GUIDE ON PAGES 4-7 OF YOUR RESOURCE BOOK TO TRY TO IDENTIFY SOME OF THE ORGANISMS THAT YOU ARE OBSERVING

41. Debrief
Did you see anything alive in there when you put your pond together? Where do you think all those organisms came from ? How did they get in your ponds?

42. Some microorganisms can lapse into a state of diapause, which is sort of like hibernation. During diapause the organism is sealed tightly against the outside environment. In this state it can blow around in the wind or lay on the dry ground, awaiting proper conditions to resume its aquatic existence.

43. Now where do you think the organisms in the pond came from?
What do you think might happen to these organisms if the water evaporates?
When we are through investigating our ponds, how should we dispose of them?
Students may suggest putting them into a large jar to keep in the room. Or they can be dumped out in the area where they were originally collected.

44. Storyboard
In journal, use 9 or more events to follow the life of any of the three organisms from diapause to full life.
Include:
Cause/effect
Sequence of events
Diapause
Characteristics of life