Microscopes

Question 1

What are the advantages of light microscopes?

Answer 1

• Cheap to buy and use
• small and portable
• Easy and portable
• can see colour
• specimens can be living or dead

Question 2

What is a characteristic of light microscopes regarding portability?

Answer 2

Small and portable

This makes light microscopes suitable for various settings, including fieldwork.

Question 3

What can be observed using light microscopes?

Answer 3

Living or dead specimens

This versatility allows for a wide range of biological studies.

Question 4

What is the resolution limit of light microscopes?

Answer 4

Up to 0.2 micrometers (2 x 10^-7 m)

This resolution allows for the observation of cellular structures.

Question 5

What is a feature of light microscopes regarding color?

Answer 5

Can see color (unless a stain is used)

Question 6

What are the disadvantages of electron microscopes?

Answer 6

• Expensive to buy and use
(The high cost limits accessibility to advanced laboratories.)
• Heavy and difficult to move
• Complex sample preparation
• Black and white
• Specimens must be dead

Question 7

What is a key feature of sample preparation for electron microscopes?

Answer 7

Complex to prepare a sample and must be dead

This complexity often requires specialized skills and equipment.

Question 8

What type of image do electron microscopes produce?

Answer 8

Black and white (color is added by computer)

This is due to the nature of electron imaging techniques.

Question 9

What types of specimens can be used in electron microscopy?

Answer 9

Must be dead

This requirement is due to the vacuum environment needed for electron microscopy.

Question 10

What is the resolution limit of electron microscopes?

Answer 10

Up to 0.1 nm (1 x 10^-10 m)

This high resolution allows for the observation of atomic structures.

Question 11

What type of image does transmission electron microscopy provide?

Answer 11

More magnified image

This technique allows for detailed internal examination of specimens.

Question 12

What is the advantage of scanning electron microscopy?

Answer 12

3D image

This allows for a better understanding of the surface structure of specimens.

Question 13

What stains are used and what are they for

Answer 13

Staining is often necessary to enhance contrast in certain specimens.
Iodine - plant cells
Methylene Blue - animal cell
Crystal violet - bacteria cell

Question 14

What advantage to electron microscopes have over light microscopes

Answer 14

Electron microscopes have a much higher resolution there for can see much more detail than a light microscope

Question 15

How to calculate magnification of a drawing

Answer 15

Magnification of a drawing = size of image/
actual size

Question 16

How to calculate magnification power

Answer 16

Magnification of eyepiece lens X magnification of the objective lens