Microscopy and cell size
18 review questions with answers for Microscopy and cell size. Read them here, or play the set as a class game on the projector. Free to host, and students join with a code.
Magnification is calculated as…?
- Image size ÷ actual sizeRight answer
- Actual size ÷ image size
- Image size × actual size
- Actual size − image size
What this set covers
Magnification, resolution and units run through this set, from light and electron microscopes to micrometres and nanometres, with worked sizes for cells and bacteria, staining with methylene blue or iodine, and how to focus a slide.
- Common mix-up
- Students often mix up magnification and resolution: magnification only makes an image bigger, while resolution is what lets two close points be seen as separate.
- Review tip
- Rearrange the magnification triangle three ways with a made-up image size and real size, then convert each answer between millimeters, micrometers and nanometers before checking.
All 18 questions and answers
Magnification is calculated as…?
Answer: Image size ÷ actual size
Ability to distinguish two points that are close together as separate?
Answer: Resolution
Instrument able to resolve individual ribosomes inside a cell?
Answer: Electron microscope
Instrument that gives detailed 3D images of the surface of a pollen grain at ×10 000?
Answer: Scanning electron microscope
Approximate limit of resolution of a light microscope?
Answer: 200 nm
Number of nanometres in one micrometre?
Answer: 1000
Unit equal to one-thousandth of a millimetre?
Answer: Micrometre
Total magnification with a ×10 eyepiece and a ×40 objective?
Answer: ×400
Magnification of an image 5 mm long of a cell that is really 50 µm long?
Answer: ×100
Real length of a cell that measures 20 mm in a drawing at ×1000?
Answer: 20 µm
Typical diameter range of an animal cell?
Answer: 10–30 µm
Typical length range of a bacterium?
Answer: 1–5 µm
Dark stain commonly used to show the nuclei of human cheek cells?
Answer: Methylene blue
Yellow-brown stain often added to onion epidermis to make nuclei visible?
Answer: Iodine solution
Thin square of glass lowered over a specimen on a slide?
Answer: Coverslip
Part on the rotating nosepiece that sits just above the specimen?
Answer: Objective lens
Control used first, at low power, to bring a specimen roughly into view?
Answer: Coarse focus
Electron microscopes cannot view living cells because the sample must be held in a…?
Answer: Vacuum
Play it as a class game
Play this set opens it in splycr, where you can host it for your class straight away. Hosting needs no account: put the room code on the projector, and students join from a phone with the code and their first name. Each question plays as multiple choice, and the three wrong options were written for that question.