By Alessandra Romero, Garrett Morgan Academy
Observing two Elodea plant cells under a microscope by using aquarium water, 3% salt
water, and determining the effects caused by those solutions.
IntWrhodatucetfifone:ctdoesthe3%saltwatersolutionhaveonanElodeaplant?
· Put 2-3 drops of aquarium water on one leaf and
T
2-3 drops of 3% salt water solution on the other
he Elodea leaf is a common aquarium plant; often cal ed
leaf (Make sure the two liquids do not combine.
the waterweed and it lives in aquarium water in ponds,
If they do, discard the slide and start over.)
streams and lakes throughout North America (2). Osmosis
· Hold coverslip by the sides and lower it gently on
is the diffusion of water across a cel 's outer membrane
top of each leaf.
from areas of high to low water concentration. It can be
· Adjust the coverslip and remove any excess water
harmful to cel s causing plasmolysis (cel water loss).
with tissue.
However, most cel s live in an environment where the
· Place the Elodea leaf cel slide on the microscope stage
movement of water is almost equal. This results in no
· Focus first with the lowest power on microscope and
harmful effects to the cel (1). In this lab we wil be
then with a higher power.
observing two Elodea piant cel s by using the materials
listed below to determine the effects that different solutions
· Adjust lens and search for both plant cel s by moving
the slide across the microscope stage.
wil cause on them. First we wil observe one of the plant
· Observe the shape of cel s and the location of chloro
cel s with aquarium water under a microscope and then
plasts, cel wal s, and cel membranes.
we wil observe the other plant cel with 3% salt water.
· Draw what you see on a piece of paper to keep for
We wil then be able to identify the location of chloroplasts,
your data and analysis.
cel wal s, and cel membranes.
· At the end of lab, dispose the slide. .
My hypothesis is that the cel wil swel when placed
in the 3% salt water solution.
Materials:
· Aquarium water
· Elodea plant
· 3% NaCl solution
· Microscope
(salt water)
· Clean slide
· Paper towels or
· Two Cover slips
tissues
· Dropper
· Gloves
My results did not support my hypothesis. The cel s did
not swel ; they actual y shrunk in the 3% salt water
· Prepare your lab section with al your materials
solution. It was a hypertonic solution. During this lab
· Remover hair out the way with a ponytail (if you
we got the chance to observe how an Elodea plant cel
have long hair)
looks like while using a high and low power on the
· Put on your gloves and rol up your sleeves
microscope. We also got to see the diffusion of water on
· Connect and tum on microscope
the plants and how the two different solutions caused the
·Place one Elodea leaf on the left side of slide and
cel s to react. We learned that when the living cel s are
an other leaf on the right side. (Make sure they do
placed into an environment where the water concentration
not touch)
inside the cel is higher than the outside of the cel , it can
28
result in plasmolysis which is cel water ioss (2).