1. #Title: The kingdoms in a water drop: an introduction to microscopy and the kingdoms of life
#Targeted Level: Middle School
#Difficulty: Intermediate 3
#Time Required: 1 hour if water samples are provided; 1 day if water samples need to be
collected
#Notes on Time Required: Natural water samples vary by how many living organisms can
be found in a given volume. If the sample is highly concentrated (many critters in a given
volume), you won’t have to spend much time searching with the microscope. If the sample is
dilute (few critters in a given volume), you will need to allow more time to find a good sample to
make your observations.
#Prerequisites: This lab will instruct the student on how to use a microscope.
#Material Availability: (2) requires specialty items but access to a laboratory is not
required.
#Material Availability Notes: You will need access to a pond or pond water samples.
You will also need access to a compound light microscope to examine the samples.
#Cost: Low (if microscope available)
#Adult Supervision Required: Yes (handling of microscope)
#Safety: Practice good hygiene after collecting and handling water samples from a pond.
Some ponds may contain pollutants or fecal material (such as from water fowl, fish or sewage).
#Abstract:
[Note: A short summary, description of the project]
[Insert]
#Objective: To gain an understanding of the kingdoms of life and the classification of aquatic
organisms. To learn to use a compound light microscope to make observations of living
organisms.
#Hypothesis:
#Credits: Jessica Watson

2. #Background:
Close your eyes and picture a kingdom. What do you see? Do you picture a castle with walls?
Are there farms in the distance? A King on his throne and knights in armor? What would you
say if someone told you a kingdom can fit in a water drop? That sometimes there can be as
many as 5 kingdoms in a water drop? Would you believe them?
Well, you are both right. There is more than one kind of kingdom. The first kind, which you may
have pictured at first, is a kingdom ruled by a king. The second kind refers to living things,
organisms that eat, breathe, move and reproduce. Biological classification is a system
scientists use to organize life into categories based on similarities and differences. Scientists
group organisms into 5 or 6 different kingdoms of life. The kingdoms of life are Plant, Animal,
Protist, Fungi, Eubacteria and Archaebacteria. The last two kingdoms are sometimes grouped
into one kingdom called Monera.
Plants get their energy from the sun. For this reason plants tend to be the colors of the
pigments they use to capture sunlight, such as green, red or orange. Animals get their energy
by eating other living organisms. When they get hungry they might eat plants, other animals,
protists, fungi or even bacteria. Protists are a tricky group. They can have things in common
with both plants and animals. Fungi include yeast, mold and mushrooms. Bacteria are
everywhere, including on your hands and in your mouth, but you won’t see them!
Salt, sugar and water are molecules that are contained in the food you eat every day. Maybe
you prefer sugar to salt? Maybe you eat too much salt and don’t drink enough water? They are
all made up of basic units called atoms. Atoms are like links in a chain. Like molecules, living
organisms are made up of basic units called cells. Cells allow the organism to breathe, eat,
move and reproduce. Since the smallest cells are smaller than a pencil tip, we need to use a
microscope in order to see very small organisms, which are made up of one or a few cells.
Microscopes enlarge organisms that we can’t see with our eyes.
In this project you are going to identify several kingdoms of life in a water sample. First, you will
collect water from a pond or lake, then bring it back to your microscope for observation. In order
to observe these small creatures, you will make a wet mount. Wet mounts are slides
containing your sample in solution; they are used to observe living organisms.
#Terms and Concepts:
biological classification
microscope
cells
kingdoms
eyepiece
stage
wet mount

3. #Questions:
1. What differences did you notice between plants that live in the water (aquatic) and plants that
live on land (terrestrial)?
2. What differences did you notice between animals that live in water (aquatic) and animals that
live on land (terrestrial)?
#Bibliography:
#Materials and Equipment:
bucket or glass jars with screw tops
Compound light microscope
Glass microscope slides (only need a few; they can be rinsed and reused)
Cover slips for slides (1 box; easier to use a new one for each wet mount)
Eyedropper
Paper and pencil
Wagon or cart (if assistance is needed carrying the bucket or jars of water)
#Experimental Procedure:

4. 1) Gather together your collecting materials: bucket or jars with screw tops, and cart or
wagon to carry them back. Locate a pond that you can access to collect water samples.
The pond should have a shore that you can reach by foot.
2) Fill your bucket or jars with water. Please note that when you submerge your bucket in
water, it can be very difficult to lift back out. When you fill the bucket, hold it with both
hands. To fill the bucket, first tilt it slowly, then push a small part of the rim into the water
so that it fills slowly. You will feel the bucket get heavy as it starts to fill. Pull it out of the
water before it gets too heavy.
3) If you have filled glass jars with water, loosely tighten the screw cap. If the cap is too
tight the organisms in the water might run out of oxygen. Since you want to see live
organisms under the microscope, keep the caps loosened so oxygen can enter the jar.
4) Bring the water samples back for observation under the compound light microscope. To
do this you are going to prepare a wet mount.
5) To prepare the wet mount, use an eyedropper to transfer some of your water sample to
a microscope slide. Handle the slide by its edges to avoid getting fingerprints on it. You
will only need to put 1-2 drops of water on the slide. If you put too much water the slide
will overflow.
6) Next place a cover slip over the water on the slide. To place the cover slip, hold it by its
edges and put one edge down on slide first. Lower the rest of the cover slip onto the
slide as if it is a hinged door. It will contact the water and cause it to spread underneath
the cover slip. It’s okay if some water spills off the sides; you have plenty more!! (see
drawing)

5. 7) Refer to the diagram showing the parts of a microscope. Place the wet mount on the
stage of the microscope and look through the eyepiece to begin making observations.
Start at the lowest magnification by using the 4x objective lens. The images you see
through the eyepiece are made larger by different lenses or pieces of glass.
8) Once you think you have the water sample in focus, move to the next highest
magnification (10x). Continue to increase your magnification, getting the water into
focus each time, until you start to see critters swimming around. You will notice that the
water on the slide has some depth so you may need to adjust with the fine focus as the
critters swim up and down.
9) If you don’t find any organisms on the slide, you may need to repeat steps 5-8 until you
do see things swimming around.
10) Once you have found some organisms to observe, begin making sketches of what you
see on each slide. Some critters may move very fast and some slow. Observe as many
as you can and make notes about sizes, color and behavior.
11) After you have observed at least 10 different organisms, begin to make guesses about
which kingdom the organism may be classified in. Add these guesses to your notes and
include the reasons you chose those kingdoms.

7. #Discussion:
Were the organisms in Kingdom Plantae more mobile than organisms in Kingdom Animal? Why
or why not?
Were the organisms in your water sample primarily from one Kingdom? If so, why do you think
this is? If not, why not?
Were there any kingdoms you did not observe under the microscope? Why or why not?
#Make it Your Own:
Do some research to answer the following questions:
Which kingdom of life has the largest living organism(s)?
Which kingdom of life has the smallest living organism(s)?
Which kingdom of life has the longest-lived organism(s)?
Which kingdom of life has the shortest-lived organism(s)?
#Answers to Questions:
1) Most aquatic plants are single-celled, with the exception of seaweed and sea grasses, among
others. This is a better adaptation for life in water because they will be less likely to sink and
can move around to find better living conditions. Terrestrial plants, like redwood trees, can get
extremely large. On land being large doesn’t limit plants because they are rooted in soil, which
is where they get their nutrients.
2)
There
can
be
more
than
one
answer
to
this
question.
Aquatic
animals
can
also
be
much
smaller
than
terrestrial
animals,
depending
on
the
stage
of
its
development.
For
example,
copepods,
which
are
arthropods
like
insects,
need
to
be
viewed
with
a
microscope.