Download Investigation 2 EXPIRIMENT: PROBLEM: formulate a hypothesis for

Investigation 2 EXPIRIMENT:
PROBLEM: formulate a hypothesis for: How are plant and animal cells alike? How are they different?
MATERIALS: dissecting needle
Medicine dropper
Elodea leaf
Microscope slide
Microscope
Prepared slide of human skin cells
PROCEDURE:
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Get microscope and place it 10 cm from edge of table.
Clean eyepiece and objective lens with lens paper.
Place a drop of water in center of a clean microscope slide.
Remove leaf from elodea leaf and place it on top of the water.
Place cover slip over water and elodea leaf.
Place slide on microscope.
Start with low-power lens.
Switch to high-power lens.
Observe elodea leaf draw and label what you see , record the magnification of microscope.
Clean and dry slide.
PART B. EXAMINING ANIMAL CELLS
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Place slide of human cells (scrape inside of cheek) center of slide directly over opening of stage.
Low-power lens locate some cells. Will need to reduce light and adjust diaphragm.
Switch to high-power lens.
Observe cells, sketch and label what you see in appropriate place in observation, record mag.
OBSERVATIONS:
Magnification
high
Magnification high
^ circle. Elodea cells (plant cells)
^circle. Human Skin cells (animal cells)
FIGURE 2
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What is the shape of the Elodea cell?
What is the general location of the nucleus of the Elodea cell?
What is the shape of the human skin cell?
What is the general location of the nucleus of the Human skin cell?
ANALYZE AND CONCLUDE
1. How are plant and animal cells similar in structure?
2. How are plant and animal cells different in structure?
THINKING SKILLS AND APPLICATION
1. What is an advantage of using wet-mount preparation instead of dry-mount preparation in the
study of living cells?
2. Explain why you could nor use an oak leaf in this investigation.
3. In general, the surface of a tree has a harder “feel” than does the surface of a dog. What cell
characteristic of each organism can be used to explain this difference?
4. If you were given a slide containing living cells of an unknown organism, how would you identify
the cells as either plant or animal?
MORE TO EXPLORE
1. Skin from fruits and veggies (tomatoes, onions, leeks) prepare wet-mount slides for each skin
and observe cells under low-power and high-power , sketch and lable