Topic 1a - cell structure and cell division ( 2. Microscopy )

Question 1

what are microscopes?

Answer 1

microscopes let us see things that we can’t with the naked eye, such as individual cells.

Question 2

what are the 2 types of microscope?

Answer 2

light and electron

Question 3

what are light microscopes?

Answer 3

light microscopes use light and lenses to form an image and make the specimen look bigger. they let us see individual cells and large cell structures.

Question 4

what are electron microscopes?

Answer 4

uses electrons instead of light and lenses. they have a much higher magnification and resolution than light microscopes. This means electron microscopes can see smaller sub cellular structures. the image of the magnifies specimen is created by electrons.

Question 5

equation for magnification :

Answer 5

magnification = image size / actual size

Question 6

state the steps for preparing a microscope slide

Answer 6

1. add a drop of water in the middle of the slide to clean it
2. cut up an onion and separate it out into layers use tweezers to peel off the epidermal tissue of the onion
3. using tweezers place the tissue onto the slide with water
4. add a drop of iodine so we can see the different cells.
5. place coverslip on top.

Question 7

state the steps for observing the specimen

Answer 7

1. start by clipping the slide you have prepared onto the stage.
2. select the lowest powered objective lens (which produces the least amount of magnification)
3. use the coarse adjustment knob to move the stage up.
4. look into the eyepiece and adjust the fine adjustment knob until the image is in focus.

Question 8

how to convert to micrometers to nanometers

Answer 8

x1000

Question 9

how to convert from micrometer to millimetre

Answer 9

/1000