microscopy

Question 1

what are the two different microscopes

Answer 1

1) light microscope
2) electron microscope

Question 2

what is a light microscope
2 points

Answer 2

1) they use light and lenses to form an image and magnify it
2) they let us see individual cells and large subcellular structures

Question 3

what is an electron microscope
3 points

Answer 3

1) they use electrons instead of light to form an image
2) they have a much higher magnification and a higher resolution
3) they let us see much smaller things in more detail like ribosomes and plasmids

Question 4

what is the formula for magnification

Answer 4

magnification= image size / real size

Question 5

what is the conversion between micrometres (µm) to millimetres (mm)

Answer 5

1000µm = 1mm

Question 6

what is 0.0025 in standard form

Answer 6

2.5 x 10^-3

Question 7

what are the parts of a light microscope
6 points

Answer 7

1) eyepiece lens
2) high and low power objectives lenses
3) coarse adjustment knob
4) fine adjustment knob
5) the stage
6) the light

Question 9

label a light microscope

Answer 9

look at page 19 of AQA biology book

Question 10

how would i prepare a slide to view onion cells
5 steps

Answer 10

1) add a drop of water to the middle of a clean slide
2) cut up an onion and separate them into layers, use tweezers to peel of some epidermal tissue
3) using the tweezers place epidermal tissue onto the slide
4) add a drop of iodine solution as a stain to the tissue
5) place a cover slip on top of the tissue making sure no air bubbles underneath

Question 11

what is a stain

Answer 11

stains are used to highlight objects in a cell by adding colour to them

Question 12

what magnification should you always start with and why

Answer 12

the lowest magnification so you have the highest field of view, so it’s easier to locate specimen