Microscopic Life Day 1 Elodea Leaves Last week

Microscopic Life

Day 1 - Elodea Leaves � 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

Page 15 � Start with 100 x magnification � Describe what you see � Increase to 400 x 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

Slide set up � 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

Discussion � 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

Discussion Continued � 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

Day 2 - Paramecium Slide set up � 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

Finding the Paramecium � Start on 40 x 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

Discussion � 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

Protists 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 �

Living vs. Organism � 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

Paramecia Feeding � 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 100 x and then at 400 x. Record observations in words and illustration

Color Change � 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?

Things to think about 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? �

Let’s Talk � What did you observe? � If you noticed bubbles inside the paramecium getting bigger and then appearing to burst, those are called waterexpelling vesicles � Hairlike structures covering exterior of the paramecia are called cilia and help the paramecia move