Microscopes + RP (P1) Flashcards
How many metres is a micrometre?
0.000001
What is a micrometre in standard form?
10 to the -6
How many metres is a nanometre?
0.000000001
What is a nanometre in standard form?
10 to the -9
How do you work out magnification?
Size of image/size of object
What is the definition of Magnification?
A degree to which something can be viewed as larger than it is
What is the definition of resolution ?
The shortest distance between two points that can still be distinguished by the observer as opposite entities
Disadvantages of a light microscope
Can’t see inside a nucleus
Limited resolution
Electron microscope advantages
Much larger magnification and resolution
What magnification can light microscopes have?
1000-2000 *
Electron microscope magnification
2 million x
Black and white
Preparing the slide
- Cut a one cell thick layer of onion
- Put it onto a microscope slide with one drop of water on it
- Put two drops of iodine on it
- Gently put a coverslip on with no air bubbles
Setting up the microscope
- Put the slide on the stage and clip it on
- Use the lowest power lens
- Looking on from the side, turn the coarse adjustment lens until it is almost touching the slide
- Look into it and turn the same knob the other way until it is focused
Looking at the slide
- Rotate the nosepiece to a higher power objective lens
- Look on at 40x until you find some cells
- When you have found one, increase the magnification
- Measure the image
- Do image size/magnification to find the object size
Where is the diaphragm and nosepiece?
Diaphragm is underneath the stage
Nosepiece is above the lenses
