Microscopy Flashcards
(16 cards)
What is the primary function of microscopes in biology?
To see things that we can’t see with the naked eye
Microscopes allow for the study of cells and subcellular structures.
What do light microscopes use to form an image?
Light and lenses
They are capable of magnifying individual cells and large subcellular structures.
How do electron microscopes differ from light microscopes?
They use electrons instead of light
Electron microscopes have higher magnification and resolution.
What is resolution in microscopy?
The ability to distinguish between two points
Higher resolution gives a sharper image.
What can electron microscopes reveal that light microscopes cannot?
Smaller details like internal structures of mitochondria and chloroplasts
They can also visualize ribosomes and plasmids.
What is the formula for calculating magnification?
magnification = image size / real size
Both image size and real size must be in the same units.
How do you rearrange the magnification formula to find image size?
image size = magnification x real size
This formula can be used to calculate either image or real size.
What is the image size of a specimen that is 50 um wide under a magnification of × 100?
5000 um or 5 mm
To convert from micrometres to millimetres, divide by 1000.
Why is standard form useful in microscopy?
To manage very big or small numbers
Standard form makes it easier to handle measurements of tiny objects.
How do you convert 0.0025 mm into standard form?
2.5 × 10^-3
The decimal point moves to the right for negative powers.
What is the first step in preparing a specimen for viewing under a microscope?
Add a drop of water
This is part of the process to create a wet mount.
What should you do after placing a cover slip on a specimen?
Try not to trap air bubbles
Air bubbles can interfere with viewing the specimen.
What is the proper sequence for using a light microscope?
Clip the slide, select the objective lens, use the coarse focus, look down the eyepiece, adjust the fine focus
This ensures a clear view of the specimen.
What should you remember when drawing a specimen viewed under a microscope?
Label all parts clearly
Drawings should be made with accuracy and clarity.
What is the magnification if an onion cell’s image is 7.5 mm wide and you want to find its real width?
Real width = image size / magnification
This calculation will require converting units to obtain the answer in micrometres.
True or False: Electron microscopes have lower resolution compared to light microscopes.
False
Electron microscopes provide higher resolution images.
