Lesson 3

The kit provides the clip on microscope, a slide, a cover slip and pipette for each student.
Not provided are the elodea plants (common aquarium plant) and water.
Observe that the cytoplasm of cells is in motion – cytoplasmic streaming.
Directly observe chloroplasts. Draw and label visible parts of the plant cell.
Learn about photosynthesis and its importance to both plants and animals.

1 What did you do last time? 2 cytoplasm cell wall nucleus plasma membrane microscope PRINT the word next
to the image on the next slide.
Cells - L3 mic pla nuc cel cyt
4 Last time you looked at a pre-made microscope slide and
then examined your own slide of onion cells.
Those cells looked like still, lifeless bricks.
But looks can be deceiving!
5 1 microscope slide 1 coverslip
This slide requires only one small leaf and a drop of tap water. What makes a plant green? tweezers
an elodea leaf --
an aquarium plant
This leaf has only two
layers of cells.
toothpick To answer this question
find these items:
water one pipette
6 Position one edge
of the coverslip
over the
elodea leaf,
as shown.
To AVOID trapping air bubbles,
let the cover slip gently drop onto
the wet tissue. Be sure the coverslip lays flat and that there are no air bubbles.
3 4 Remove a
single leaf
from your
elodea plant
and place it
on the slide.
Use the pipette to put
a small drop of tap water
onto the elodea leaf.
Blot up
the excess water
on the OUTSIDE of the
coverslip with paper.
5 6
7 Don't forget! Turn on the light source! Summary of Direction

1. Use the two metal clips to hold
the microscope slide in place.

2. Center the sample over
over the microscope lens.

3. Turn on the light source.

4. Pinch open the clamp.

5. Gently line up the microscope
lens with the camera lens.
The cells will come into view
WHEN the two lenses are lined up.

6. Now use the clamp to hold
the microscope in place over the camera lens on the device.
To use your microscope,
follow the directions in the video.
8 chloroplasts Look at your slide under the microscope.
Do you see the intensely green coloration within each cell?
This coloration is caused by compartments within each plant cell called
9 Draw in
This is a close-up view
of elodea cells.
What do you see?
10 Elodea Cells Again they look like stacked bricks.
Recall that the interlocking of many
cells gives strength and form to the roots, stems and leaves of a plant.
This is a close-up view of one of the two cell layers in elodea. These cells are larger and less elongated than the cells in the other layer. Cells are the building blocks of plants.
11 Click for answer. Click for answer. The NUCLEUS contains the recipe
for making each cell. This information is called “genetic” information.
The genetic information in the nucleus is encrypted in the molecule called -- Deoxyribo Nucleic Acid -- DNA!
Do you see the dense round structure
inside the enlarged elodea cell?
This NUCLEUS is often obscured by the chloroplasts. Label it.

What does the nucleus DO
A close-up view of
one elodea cell
with the nucleus visible.
Do you see that each individual plant cell
is surrounded by a thick surface or wall?
Label this the CELL WALL.

What does the cell wall DO
Plant cells have CELL WALLS that:

• protect the cell
• maintain the cell’s shape
• prevent excessive water uptake
• are made up of cellulose
12 Inside the cell wall is an inner sack
that encircles the cell. It is difficult
to distinguish at this magnification
but label it the PLASMA MEMBRANE.

What does the plasma membrane DO
It performs many functions in a cell.
The CYTOPLASM in elodea is packed with chloroplasts. The chloroplasts use sunlight,
water and carbon dioxide to make sugar.
Chloroplasts are sugar factories!

controls what goes in and out of a cell.
The CYTOPLASM is the area INSIDE each cell
that is OUTSIDE the nucleus.
Label it on your elodea cell diagram.

What does the cytoplasm DO
plasma membrane cytoplasm
Preparing the slide Seeing at higher magnifications The Elodea Leaf
14 The chloroplasts also release a fabulous
waste product -- oxygen (O2)!
This O2 goes into the air and is
the very oxygen that you need to breathe.
Within the chloroplasts, plants capture the energy from sunshine
and use it to combine two simple molecules: carbon dioxide (CO2) from the air and
water (H2O) from the ground to make sugar!
Chloroplasts are sugar making factories! sugar oxygen water carbon
sunlight Photosynthesis CO2 O2 H2O C6H12O6 Chloroplasts are itty-bitty green bags
inside plant cells that capture energy
from sunlight to make sugar.
15 Oh, what a difference photosynthesis
has made to life on this planet.
People cannot survive without photosynthesis because humans
and all animals must breathe
in oxygen to live!
O2 O2 O2 O2 O2 OXYGEN (O2)
From Photosynthesis
16 No plants, no food, no us! Light + H2O + CO2 = Sugars + O2 Photosynthesis O2 CO2 Sunlight Eats carbohydrates
stored in the plants.
H2O Animals, including people, must eat to live.

We need energy from food.

We cannot make our own food as plants do
from sunlight and basic ingredients (H2O, CO2).

So we must eat plants
or other animals that
eat plants to survive.
17 glucose oxygen carbon dioxide What is the formulas for each of these: CO2 H2O O2 C6H12O6 sunlight
carbon dioxide
the sugar
oxygen Name three key ingredients required for photosynthesis water Name the
key product
of photosynthesis
Name the waste product of photosynthesis Photosynthesis
18 More on Photosynthesis from Mr. Anderson 19 Chloroplasts are Streaming! 20 Plant Cells Crash Course on Plant Cells Cells that nearly killed world! 21 Plants have a rigid
outer layer made of cellulose. Name it.
The organelle
inside a plant cell that stores most of the DNA.
What is a waste product
of photosynthesis
What makes
a plant green
1 2 3 4 5 What do the
chloroplasts do
Chlorophyll: it REFLECTS the green wavelengths of white light! the cell wall the nucleus O2 - oxygen they use sunlight, water and carbon dioxide to make glucose, a sugar.