Using a Microscope

Science · Organisms & Life Processes · ages 11-12

Name ______________________ Date ____________

What do you place over a wet mount slide after adding the specimen and a drop of water?
- A coverslip
- A second slide
- A lens cap
Look at the focusing steps below. What should you do first?
- Start on lowest power, use coarse focus
- Start on highest power and use fine focus
- Skip straight to fine focus
While bringing the objective and slide closer together, you should look through the eyepiece instead of watching the gap from the side.
Circle one: True False
Priya lowers her coverslip straight down flat onto the slide. What is most likely to happen?
- Trapped air bubbles
- A dissolved specimen
- A larger microscope image
A drawn cell measures 6 mm across. The real cell is 0.06 mm wide. What is the magnification? Type just the number.
Answer: ______________
Which pair helps a reader identify cell parts and judge their real size in a microscope drawing?
- Color shading and a border
- A title and the lens power
- A scale line and labels
A specimen is really 0.05 mm wide. A drawing shows it at 200 times its actual size. How wide is the drawing, in mm?
Answer: ______________
Tom draws the onion cells he sees, but adds extra lines that aren't really there because he thinks the drawing 'looks better'. What is wrong with what Tom did?
- He should have used more color instead
- He should draw only observed details
- Nothing is wrong, drawings should look neat

Answer key

For grown-ups. Fold this page away before handing over the rest.

A coverslip · A coverslip keeps the specimen flat and protected so light can pass through clearly.
Start on lowest power, use coarse focus · Starting on low power with coarse focus makes it much easier to find your specimen before sharpening the image.
False · Watch the gap from the side while bringing the objective and slide closer. Stop before they touch. Look through the eyepiece when focusing by increasing the gap.
Trapped air bubbles · Lowering a coverslip flat can trap air bubbles. Tilting it down from one edge helps air leave as the water spreads.
100 · Magnification = image size ÷ actual size, so 6 mm ÷ 0.06 mm = 100.
A scale line and labels · Labels name the observed cell parts. A measured scale line shows a real length, allowing the reader to judge the specimen's size.
10 · Drawing width = magnification × actual width, so 200 × 0.05 mm = 10 mm.
He should draw only observed details · Scientific drawings record what's really seen, not what looks nicer. Adding details that aren't there makes the drawing inaccurate.