Microscopes

Question 1

magnification

Answer 1

how many times bigger the image is compared to the actual specimen

Question 2

specimen

Answer 2

material put under the microscope

Question 3

image

Answer 3

appearance of the material when viewed under a microscope

Question 4

resolution

Answer 4

how well a microscope distinguishes between two points
high resolving power- more detailed and clearer image
shows internal structure of organelles
electron microscopes have higher resolution as electrons have shorter wavelength than light so can distinguish between two points

Question 5

light microscope

Answer 5

energy= light
mag= 1500 (low)
res= 200nm (low)
specimen= live or dead 
stain= colour eg iodine
image= 2D

Question 6

scanning electron

Answer 6

energy= electrons
mag= x100,000 (high)
reso= 10nm (high)
specimen= dead (vacuum)
stain= no stain
image=3D

Question 7

transmission electron

Answer 7

electrons pass through specimen;
denser parts absorb more electrons;
denser parts appear darker;
electrons have short wavelength so give high resolution

energy= electrons
mag= 250,000 x (very high)
reso= 1nm (very high)
specimen= dead (vacuum)
stain= no but heavy metals used
image= 2D

Question 8

artefacts

Answer 8

TEM requires complex preparation of specimen
something observed in a scientific investigation that is not naturally present but occurs as a result of the preparative procedure
may get confused with the structure of the cell

Question 9

temporary mount

Answer 9

put a drop of water on the glass slide
obtain the thin specimen (one cell thick) and put on the slide
add stain to specimen eg iodine
use mounted needle to place cover slip on

Question 10

graticule

Answer 10

glass disc that is placed on eyepiece and has scale on it which can be used to measure the length of cells

Question 11

measuring length of cells

Answer 11

put a ruler on slide and magnify so 1mm shows in field of view
count how many cells are in 1mm
calculate length of cell - 1mm/ number of cells
count a large amount to calculate mean
convert mm to um