 Last week we looked at our cheek cells under the microscope  Today, we are going to be looking at a different kind of microscopic life  Open your folders to page 15

 Start with 100x magnification  Describe what you see  Increase to 400x magnification  Describe what you see and draw it in the field of view  Estimate the size of the cells in the leaf Record any additional observations

 Get a slide and a dropper from your microscope kit.  Bring it to the Elodea station  Break off half a leaf from the stem  Place the leaf, top side up, on your slide  Using your dropper, add a drop of the Elodea water to your slide  Cover with a coverslip

 What do you see when you look at the Elodea?  Do the cells look empty?  How many layers of cells do you see? › 2, one large and one small

 Are all of the Elodea cells the same size? › No, some are big and some are small  Are the cells on the large cells on the top of the leaf or bottom of the leaf? › The larger cells are on top  How big are the Elodea cells? › The larger ones are about 0.1 mm and the smaller ones are about 0.05 mm

 Use a dropper to collect some water from the bottom of the paramecium container  Add 1 drop to your slide  Place a VERY SMALL amount of spread out cotton on top  Cover with a cover slip

 Start on 40x and look for tiny ovals moving around  Open to page 16 of your notebook and answer the questions  After you find your paramecium, change the lighting using the diaphragm to see different details

 What movements did you observe? › The paramecium was moving around the slide and there were moving circles inside the paramecium  What did you see on the inside of the paramecium? › Blobs, circles, dark areas  What did you see on the outside of the paramecium? › Little legs or hairs  How big was the paramecium? › Less than 0.5 mm

 Are they living or nonliving? › living  What is your evidence? › They are moving  Could you see it eat or use energy? Give off waste? Reproduce? › no  What might we do to see some of these activities? › Feed them

 Paramecia are single-celled organisms in the Protista kingdom  In Greek, proto means early and protist means the very first  The single-celled organisms like paramecia are members of a kingdom of life that are similar to some of the very first life-forms on Earth.  Protists are not animals, animals are always multicellular  Protista is a separate kingdom whose members are mostly single-celled

 Each Elodea cell is living while the paramecia cell is an organism.  The Elodea cells stay in one place; paramecia move around  Elodea cells are stuck together; paramecia cells are alone  Elodea cells are part of a bigger organism; paramecia are not

 Prepare a wet mount of paramecia with cotton just like before.  Add one drop of the Congo red-dyed yeast  Add the cover slip  Locate a paramecium and look for evidence that it is eating yeast  Observe first at 100x and then at 400x. Record observations in words and illustration

 Congo red does two things  It makes the yeast easier to see  It also acts as an acid indicator  What happened when acid was added to the Congo red?  How can Congo red be used as an indicator?

 Paramecia do not have legs or fins. How do you think they move around?  How do the paramecia get the yeast inside their bodies?  Do paramecia have mouths?  How do paramecia get rid of waste?  What keeps the paramecium’s insides from spilling out?  What does the yeast look like inside a paramecium?

 What did you observe?  If you noticed bubbles inside the paramecium getting bigger and then appearing to burst, those are called water-expelling vesicles  Hairlike structures covering exterior of the paramecia are called cilia and help the paramecia move