Required Practicals Flashcards
All topics
RQ1- Why do you use coverslips over the specimen?
It protects the microscope and prevents the slide from drying out when it’s being examined.
RQ1- How do you place a coverslip? And why?
Lowered gently from the side.
To prevent air bubbles being trapped underneath.
RQ1-What can be added to show contrast in the specimen?
Stains.
RQ1-What animal cells are used as biological samples for examination?
Cheek Cells
RQ1-What plant cells are used as biological samples for examination?
Onion epidermal cells
RQ1-What is the method for preparing a slide of cheek cells? Use diagram for the 4 steps.
-Put a small drop of water on the slide.
-Gently swab the inside of your mouth with a clean cotton swab.
-Gently rub the cotton bud in the drop of water.
-Place a coverslip over.
RQ1-What is the method for preparing a slide of onion epidermal cells? Use diagram for the 4 steps.
-Put a small drop of water on the slide.
-Peel some onion skin from an onion bulb with forceps.
-Place onion skin on the drop of water and make sure it is flat.
-Stain with iodine and place a coverslip over.
RQ1-What are the 6 steps to using a light microscope?
-Rotate to lowest lens
-Focus stage close as possible to lens.
-Place the slide in line with light
-Focus the slide towards you
-Record an image then rotate to higher lens
-Re-focus until clear and repeat
RQ1-What are risks of examining cells with a light microscope?
- Too bright illumination.
- Use of stains.
- Handling glass coverslips + slides
RQ1- What is the difference between low power and high power diagrams from light microscopes?
Low power- shows the outline of individual cells that make up the tissue.
High Power- is a detailed image of a part of the slide. It is usually drawn to show a single cell.
RQ1- What is the magnification of the microscope?
magnification of eyepiece × magnification of objective
e.g. x10 x40 = x400
