Download Investigating Cells - Miss Gleason`s Science

Investigating Cells
Name:__________________
Introduction: The Cell Theory tells us that all living organisms are made of cells. In this
lab you will make wet mount slides of various types of cells and identify structures in the
cells. You will then compare the cell parts found in plant and animal cells.
Materials: Microscope, slides, cover slips, water, iodine stain, methylene blue,
toothpicks, dropper, cork, onion bulb, Elodea plant.
General Reminder:
All sketches should have the following details:
 What is it? Every sketch should have a title.
 What is the total magnification? (Ex. 100X)
 Pay attention to details and make drawings neat. Take your time and draw what
you actually see as you look through the microscope. Do not scribble or put
meaningless dots or cross-hatching.
 Label structures.
Cork Cells:
Prepare a cork slide by thinly slicing a piece of cork and looking it under the microscope.
Or look at a prepared cork slide.
Sketch several cork cells as they appear under high magnification. Label the cell wall.
Human Cheek Cells:
Human cheek cells may be used to view plasma membrane, cytoplasm, and the nucleus.
Place a drop of methylene blue stain onto a slide. Gently scrape the inside of your cheek
with the end of a toothpick. You will not be able to see anything on the toothpick when
you remove it from your mouth. Dip the toothpick into the stain on the slide and mix
once or twice. Add a cover slip and use the eraser end of a pencil to gently tap out air
bubbles. Now look at the cheek cell under the microscope. Draw a cell and label the
plasma membrane, cytoplasm, and nucleus in the box below.
Onion Cell:
Take a very thin layer off an onion bulb, place it on a slide and put a drop of Iodine stain
on the onion. Add a cover slip and use the eraser end of a pencil to gently tap out air
bubbles. Use the microscope to look at the onion cell, sketch the onion cell below
labeling the cell wall, cytoplasm, and nucleus.
Elodea Cells:
Chloroplasts are easily seen in Elodea, a common water plant. Prepare a wet mount of an
Elodea leaflet. Using low power, position your slide so you are looking near the edge of
the leaflet. Locate the oblong cells. Examine these cells under high power. Notice the
chloroplasts and try to locate moving chloroplasts. Use the fine adjuster to view different
layers of the cell. Sketch the Elodea cell below labeling the cell wall and chloroplasts.
Analysis Questions:
1. How was the cork cell important in the development of the cell theory?
2. Does a plant or animal cell produce cork, explain your answer.
3. Describe the shape of cheek cells.
4. Based on your observations are cheek cells produced by a plant or an animal?
5. Based on your observations, what is the function of the plasma membrane?
6. Is an onion cell produced by a plant or an animal based on your observations?
7. Based on your observations, what is the function of the cell wall?
8. Is Elodea a plant or animal? Based on this lab explain how you know?
9. Are chloroplasts present in all plant cells? Explain your reasoning?
10. List 3 ways plant and animal cells differ.