Practical: Microscopy Flashcards
All 7 cards in this deck
What are the steps to prepare a slide of a thin plant specimen for a light microscope?
e.g. a peel from a leaf
- Place the thin peel flat on a slide in a drop of water.
- Add a drop of stain such as iodine.
- Lower a coverslip at an angle with a mounted needle to avoid air bubbles.
State two reasons for placing a coverslip on top of a specimen.
To keep the specimen flat and in place, and to protect the specimen and the objective lens.
Why must a specimen such as a leaf peel be thin?
So light can pass through it, allowing the cells to be seen.
Why is a stain such as iodine added to a specimen on a slide?
It increases contrast so sub-cellular structures show up more clearly.
Which objective lens should you start with when focusing a light microscope, and which focusing knob is used last?
Start with the lowest power objective lens; use the coarse focus first, then the fine focus.
What should a labelled scientific drawing of a microscope specimen include?
A title, clear unbroken pencil lines with no shading, straight label lines that do not cross, and the magnification used.
True or false? A scientific drawing of cells should be shaded to show colour.
False. Scientific drawings use clear, unshaded pencil lines with labels.