1.6 - Core Practical: Investigating Biological Specimens Flashcards
Investigating Biological Specimens
What is the eyepiece of a light microscope?
The part of the microscope that we look through to view specimens.
What is the barrel of a light microscope?
The upper part of the microscope that can be moved up or down to focus the image.
What is the turret of a light microscope?
The part of the microscope that is rotated to change the magnification lens in use.
What is the function of the lens in a light microscope?
The lens increases the magnification of the specimen.
What is the stage of a light microscope?
The flat surface on which we place the specimen.
What is the first step to use a light microscope?
Place the slide on the stage and look through the eyepiece lens.
What should you do after placing the slide on the stage?
Turn the focus wheel to obtain a clear image.
What magnification should you start with when using a light microscope?
Start with the lowest objective lens magnification.
What should you do after starting with the lowest magnification?
Increase the magnification of the objective lens and refocus.
What are the 4 steps to prepare a slide for microscopy?
- Take a thin layer of cells from your sample. 2. Add a small amount of the correct chemical stain. 3. Apply the cells to your glass slide. 4. Carefully lower a coverslip onto your slide.
How do you take a thin layer of cells for microscopy?
You can either peel them off or use a cotton bud.
What is the purpose of chemical stains in microscopy?
Chemical stains make some parts of the specimen more visible when viewed through the microscope.
What is the formula for magnification?
Magnification = measured size / actual size
How do you calculate actual size in microscopy?
Actual size = measured size / magnification
What is the formula for total magnification?
Total magnification = objective lens magnification x eyepiece lens magnification
