Microscopy

Question 1

what is the equation for magnification?

Answer 1

Question 2

How do you prepare a slide to look at onion cells?

Answer 2

1) Add a drop of water to the middle of a clean slide
2) Cut up an onion and separate it out into layers. Use tweezers to peel off
some epidermal tissue from the bottom of one of the layers
3) using the tweezers, place the epidermal tissue into the water on the slide
4) Add a drop of iodine solution. lodine solution is a stain so it is used to highlight objects by adding colour
5) Place a cover slip on top. To do this, stand the cover slip upright on the side next to the water droplet. Then carefully tilt and lower it so it covers the onion piece but avoid getting air bubbles as they’ll obstruct your view

Question 3

what does a labelled microscope look like?

Answer 3

Question 4

how would you use a light microscope to look at a slide?

Answer 4

1) Clip the slide you’ve prepared onto the stage.
2) Select the lowest-powered objective lens (i.e. the one that produces the lowest magnification).
3) Use the coarse adjustment knob to move the stage up to just below the objective lens.
4) Look down the eyepiece. Use the coarse adjustment knob to move the stage downwards until the image is roughly in focus.
5) Adjust the foous with the fine adjustment knob, until you get a clear image of what’s on the slide.
6) If you need to see the slide with greater magnification, swap to a higher-powered objective lens and refocus.

Question 5

How do electron microscopes differ to light microscopes?

Answer 5

*electron microscopes use electrons to form an image.
*electron microscopes have a much higher magnification than light microscopes
*they have a higher resolution than light microscopes so you can see much smaller things in much detail e.g.subcelluar parts like mitochondria

Question 6

what are light microscopes?

Answer 6

•light microscopes use light and lenses to form an image of specimen and magnify it.
•you can use light microscopes to see individual cells and large sub cellular structures like nuceli

Question 7

what is an order of magnitude?

Answer 7

•a power to the base 10 used to quantify and compare size
•10times bigger= 1 order of magnitude bigger, 100 times bigger= 2 orders of magnitude bigger

Question 8

what is resolution ?

Answer 8

•the ability to distinguish between two
points
•a higher resolution gives a sharper image

Question 9

how many micrometers are in 1 meter?

Answer 9

Question 10

what are micrometers represented as?

Answer 10

µm