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
Which of the focuses are higher up?
Coarse then fine
