Download Katie Chapman Elodea Lab Write Up Purpose

Katie Chapman
Elodea Lab Write Up
Purpose- The purpose for using this plant is to study the internal structure of a leaf cell and
more specifically the cell membrane, cell wall and the chloroplasts.
Hypothesis- If the amount of salt water is changed, then the Elodea leaf will be seen easier
because the more salt water you use the easier it is to see the cells.
Materials:
 One elodea leaf
 Microscope
 Slide and Cover slip
 Paper towels
 Beaker of salt water (prepared by teacher)
 Eye dropper
 Colored Pencil
Methods- Part one of the Lab: Get an elodea leaf and place it on a clean slide. Next, put one
drop of fresh water onto the leaf then put the cover slip on top of the leaf. After that put the
slide under the microscope and observe under low, medium and high power. Next, use the
coarse adjustment to focus it as clearly as possible. Then, label the chloroplasts, cell wall and
the cell membrane (only on the high power lens). Part two of the lab: Do not remove the cover
slip from slide. Place two drops of salt water on the slide, next to the cover slip and put a small
piece of paper towel on the other side. In a few seconds water will begin to show up on the
towel. After you have gotten the salt water on the leaf, make a sketch for medium and high
power, oh and be sure to label the cell wall, cell membrane and the chloroplasts, only on the
high power sketch.
Results- The cell wall and cell membrane stayed the same, but there was a change in the
number of chloroplasts.
Solution
Distilled water
10% Salt water Solution
Observations
1. Medium Power: chloroplasts was seen
2. High Power: even more chloroplasts seen
1. Medium Power: there were more
chloroplasts with salt water than with the
distilled water.
2. High Power: could see cells easier
Conclusion- Part one of the lab the cells where big, but when the salt water was added to the
leaf cells they expanded. The hypothesis was correct because the salt water showed more
Katie Chapman
chloroplasts and it was easier to see than the distilled water so that means the hypothesis was
correct.
Errors- Possible errors could be that there was not enough salt water added to the Elodea leaf,
so that the chloroplasts were more visible.
Further Study- This lab could have been different by adding different amounts of salt water and
different amounts of the distilled water to the Elodea leaf.
Analysis Questions- This lab demonstrates homeostasis by internal environment of fluid
balance, acid-base balance and environmental changes because the elodea leaf is plant life
which means it is alive.