required practical - microscopes Flashcards
1
Q
what are the 8 main labels on a microscope
A
eyepiece
eye lens
objective lens
stage
coarse focussing dial
fine focussing dial
lamp
2
Q
what is the equation for total magnification
A
magnification of eyepiece lens x magnification of objective lens
3
Q
what is the equation for calculating magnification
A
image size / actual size
4
Q
what is the actual size
A
real size of the object
5
Q
what is the image size
A
size that it appears to be after magnification
6
Q
how do you prepare an onion slide for a microscope
A
- use a dropping pipette to add a drop of water to slide
- separate a thin layer of onion
- peel of a thin layer of epidermal tissue
- use forceps to place on slide
- ensure onion is flat
- put two drops of iodine onto onion tissue
- carefully place an over slip over the slide 8. use filter paper to soak up any extra liquid
- put onto stage of microscope
7
Q
how do you view a prepared slide
A
- place slide onto stage securing with clips
- select lowest power objective lens
- slowly turn coarse focussing dial to position the lens ensuring to view from the side and ensure that lens almost touches slide
- use the fine focussing dial to bring cell into clear focus
8
Q
draw and label a microscope onion cell
A
include nucleus, cell wall, vacuole, cytoplasm