HONORS BIOLOGY PLASMOLYSIS LAB INTRODUCTION:

name:
block:
HONORS BIOLOGY
PLASMOLYSIS LAB
score:
/ 30 pts
INTRODUCTION:
Plasmolysis is the shrinking of the cytoplasm of a plant cell
in response to diffusion of water OUT of the cell and into a
hypertonic solution (high solute concentration) surrounding
the cell.
1.
Circle the box in the figure that shows plasmolysis. 1 pt.
During plasmolysis the cellular membrane pulls away from the
cell wall. In the next lab exercise you will examine the details
of the effects of highly concentrated solutions on diffusion and
cellular contents.
PROCEDURE:
Prepare a wet mount of a single Elodea leaf and a drop of
water. Observe under 400x magnification. Sketch and
describe the appearance of the leaf cells. (In sketches of microscope images, you must note the magnification in the drawing
and draw the image to scale as compared to the field.)
Elodea leaf in distilled water 5 pts.
2.
Describe the appearance of the leaf cells. Which organelles are
visible? How are they distributed in the cell in relation to the cell wall
and cell membrane? 3 pts
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3.
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Remove the cover slip and blot the leaf dry. Add 2 or 3 drops of 15% salt water
(NaCl). Replace the cover slip and view again. Plasmolysis may take some
time. Describe the appearance of the leaf cells again. Make a new sketch. (Note
the magnification.) Which organelles are visible now? How are they distributed
in the cell in relation to the cell wall and cell membrane? 3 pts
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Elodea leaf in salt water 5 pts.
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REVIEW: For all responses, use your vocabulary!
4.
What is plasmolysis? Does water move into the cell or out of it? Reread the introduction. 2 pts
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Mrs. Loyd 
[email protected]
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http://loydbiology.weebly.com
10/19/10
http://www.mybiology.com
5.
Why did the Elodea cells plasmolyze? (How does the polarity of the water molecule cause it to move due to the
addition of salt-NaCl?) 3 pts
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APPLICATION:
6.
Itʼs been a winter with heavy snowfall. The D.O.T. has worked many hours of overtime plowing and salting the
roads and streets. Spring finally arrives; the days are warm and sunny. To your dismay, you notice the grass all
along the road is dead or dying! What happened? 3 pts
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7.
What would you have to do to be able to grow grass near the road again? 3 pts
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8.
Your favorite potted plant used to be the envy of the neighborhood. It was lush and green. Lately, however, it has
begun to look pathetic (not lush and not green). You have been doing what you have always done. You watered it
from the hose and added fertilizer according to the directions. Why is it, that what you did before, isnʼt working
anymore? What would you have to do to get your plant to perk up again? 2 pts
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Mrs. Loyd 
[email protected]
Page 2 of 2
http://loydbiology.weebly.com
10/19/10
http://www.mybiology.com