Module 2- Microscopy

Question 1

what is resolution?

Answer 1

ability to see more detail + see individual objects as separate entities

Question 2

what must be included in a biological drawing?

Answer 2

-title
-no shading/crosshatching
-scale
-magnification
-smooth continuous lines
-labels cannot have arrow heads

Question 3

what is differential staining?

Answer 3

used to distinguish between two types of organism/organelles of single organism within a tissue sample

Question 4

formula for magnification?

Answer 4

mag=image size/actual size

Question 5

what is magnification?

Answer 5

how many times larger an image is compared to its actual size

Question 6

what does the objective lens of a compound light microscope do?

Answer 6

produces magnified image which is magnified again by eyepiece lens

Question 7

do transmission electron microscopes (TEM) produce 3D or 2D images?

Answer 7

2D

Question 8

do scanning electron microscopes (SEM) produce 3D or 2D images?

Answer 8

3D

Question 9

do laser scanning confocal
microscopes produce 3D or 2D images?

Answer 9

2D and 3D

Question 10

image colour of laser scanning confocal
microscope?

Answer 10

coloured

Question 11

image colour of SEM?

Answer 11

black and white

Question 12

image colour of TEM?

Answer 12

black and white

Question 13

which microscopes can look at live specimens?

Answer 13

light and laser scanning confocal

Question 14

which microscope has the best resolution and magnification?

Answer 14

SEM———–electron microscopes have around the same magnifications (500 000x)

Question 15

disadvantages of light microscope?

Answer 15

-low resolution
-poor magnification

Question 16

advantages of light microscope?

Answer 16

-can be used on live specimens
-vacuum not needed
-small + portable
-not expensive
-natural colour observed

Question 17

disadvantages of electron microscopes?

Answer 17

-black+white images produced
-vacuum required
-cannot use live specimens
-expensive

Question 18

advantages of electron microscope?

Answer 18

-high resolving power
-high magnification

Question 19

what is an artefact?

Answer 19

visible structural detail caused by processing the specimen

Question 20

which microscopes can artefacts appear in?

Answer 20

electron and light

Question 21

how are artefacts caused in light microscopy?

Answer 21

bubbles that get trapped under the coverslip when slide is prepared

Question 22

how are artefacts caused in electron microscopy?

Answer 22

changes in cell ultrastructure during process of samples

Question 23

what is a counterstain?

Answer 23

application of a second stain with a contrasting colour to sample for microscopy

Question 24

how to use an eyepiece graticule?

Answer 24

-place the stage micrometer on the stage
-line up scales of micrometer + the eyepiece graticule
-count the number of divisions on the eyepiece graticule equivalent to each division on the stage micrometre
-calculate length of one division of the eyepiece graticule