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Name ________________________
Pollen Observation through Microscopy
Introduction
Pollen are microscopic particles that plants distribute through insects, wind, etc.,
to other plants of their own species for fertilization and sexual reproduction. Pollen
particles are so small they almost look like dust, but by using a microscope, you can see
that pollen comes in different sizes and shapes.
Microscopy Directions
1. Take a slide and use a dropper to put a drop of water in the middle of the slide.
2. Use tweezers or a dissecting needle to scrape some of the pollen from your
flower onto the slide.
3. Put a coverslip on top of the drop of water, avoiding air bubbles by resting one
side of the coverslip on the slide and then dropping it into place.
4. View your pollen slide under low power (4x). Once you focus and find the pollen
(many look like small circles), increase your power and focus again.
5. Get as close as you can while still being able to see an individual pollen on your
slide.
6. Draw a single pollen and write down observations such as the texture and color.
7. Advanced: Determine the approximate size of your pollen using the directions
on the next page.
What plant is this pollen
from?
_____________________
Total magnification:
_____________________
Approximate size of
pollen:
_____________________
Other observations:
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Name ________________________
Advanced: How to determine the size of your pollen
The ocular lens (the part you look through) of your microscope has a power of
10x, so everything you look through it is ten times bigger than with your eye. This is
further magnified by the objective lens of the microscope, the lens that sits above the
sample and is changeable. Because these objects can be many times smaller than a
millimeter (mm), we often use micrometers or microns (µm) to describe their size.
There are one thousand microns in a millimeter!
1 mm = 1000 µm
1. Determine the total magnification of the object on the slide by multiplying the
power of the ocular lens by the objective lens in the table below.
2. At the lowest power, take a plastic ruler (the clear, colorless ones work best) and
put it under your lens. Look through your microscope and determine the diameter
of your field of view in millimeters.
3. Multiply that number by 1000 to determine your field of view in microns, and
record it in the table.
4. You can determine the size of the field of view for the other magnifications using
a simple algebra equation. For example, to calculate the field of view for 10x
magnification:
(1𝑠𝑡 𝑚𝑎𝑔𝑛𝑖𝑓𝑖𝑐𝑎𝑡𝑖𝑜𝑛)(𝑘𝑛𝑜𝑤𝑛 𝑓𝑖𝑒𝑙𝑑 𝑜𝑓 𝑣𝑖𝑒𝑤)
= (2𝑛𝑑 𝑚𝑎𝑔𝑛𝑖𝑓𝑖𝑐𝑎𝑡𝑖𝑜𝑛)(𝑢𝑛𝑘𝑛𝑜𝑤𝑛 𝑓𝑖𝑒𝑙𝑑 𝑜𝑓 𝑣𝑖𝑒𝑤)
(4)(5000 µ𝑚) = (10)(𝑥)
20,000 µm = 10x
x = 2,000 µm
Objective Lens
Total Magnification
4x
40x
Field of view (µm)
10x
40x
100x
5. To determine the size of your pollen, isolate a single pollen particle in your field
of view, and estimate how many particles would fit across the diameter of your
view. This will be easier if your magnification is high.
6. Divide the field of view (in µm) for the magnification you are at by the number of
pollen particles that could fit. This is the approximate size of your pollen particle.