Microscopy (Chapter 1)

Question 1

WHAT ARE THE TWO TYPES OF MICROSCOPES?

Answer 1

1. Light microphone
2. Electron microscope

Question 2

WHAT ARE THE TWO PROPERTIES OF A MICROSCOPE?

Answer 2

1. Resolution
2. Magnification

Question 3

WHAT IS RESOLUTION?

Answer 3

• It is the ability to distinguish between two separate points
• It is also the amount of clarity of the image or the amount of detail that can be seen in a specimen.
• Greater the resolution, Greater the detail.

Question 4

WHAT IS MAGNIFICATION?

Answer 4

• The number of times larger an image is the. The actual size of the object.
• When magnifying an object you are only making it larger not clearer.

Question 5

WHAT IS THE EQUATION FOR MAGNIFICATION?

Answer 5

Magnification= Image size/ Actually size

Remember it as MIA.

Question 6

WHAT IS THE RULE FOR CONVERTING UNITS?

Answer 6

Big —> Small = Multiply
Small —> Big = Divide

Question 7

WHAT IS 1 CM IN MM?

Answer 7

1cm × 10 = 10mm

Question 8

WHAT IS 1 MM IN 1 µm?

Answer 8

1mm × 1000= 1000µm

Question 9

WHAT IS 1 µM IN NM?

Answer 9

1 µm × 1000 = 1000 nm

Question 10

WHAT IS THE EQUATION FOR THE POWER OF MICROSCOPY?

Answer 10

Objective Lens × Eye Piece Lens = Power of Microscope

Question 11

WHAT IS A LIGHT MICROSCOPE?

Answer 11

A light microscope uses focused light to magnify a specimen.

Question 12

WHAT IS THE MAXIMUM RESOLUTION OF A LIGHT MICROSCOPE?

Answer 12

• 200nm
• Therefore, if two points are closer than 200nm a light microscope won’t be able to distinguish between them. Instead, we use an electron microscope.

Question 13

WHAT IS THE MAXIMUM MAGNIFICATION OF A LIGHT MICROSCOPE?

Answer 13

• 1500×
• However, after 1000× the image is not clear. It does magnify the specimen but it’s not clear.

Question 14

WHAT IS AN ELECTRON MICROSCOPE?

Answer 14

• we use electrons/electron beam to magnify a specimen

Question 15

WHAT IS THE MAXIMUM RESOLUTION OF AN ELECTRON MICROSCOPE?

Answer 15

• 0.1nm
• The wavelength of an electron microscope is shorter than the wavelength of a light microscope (200nm>).

Question 16

WHAT IS THE MAXIMUM MAGNIFICATION OF AN ELECTRON MICROSCOPE?

Answer 16

• 500000×
• view images more closer than Light microscope

Question 17

WHY DO WE USE A VACUUM CHAMBER TO VIEW OBJECTS WITH A ELECTRON MICROSCOPE?

Answer 17

• We use a vacuum to acquire a high resolution image.
• Other atoms and molecules from the air can be present in the column so the electron beam ionizes the air and scatters.
—> their interaction with the electrons causes the electron beam to deflect and reduces the image quality.
• So, we use a vacuum chamber to prevent scattering of air particles and ionization which can interfere with the magnification process.
•

Question 18

WHY DO WE DO STAINING?

Answer 18

• Some cells are transparent so light easily passes through the transparent cells. And the organelles aren’t visible.
• So with staining the cells become visible And light reflects through the cells making the organelles become visible to the eye

Question 19

WHAT ARE ELECTROMAGNETS?

Answer 19

• For the electron beam to travel vertically and allow it to focus on the object we use electromagnets which are arranged on the sides of the microscope.

Question 20

WHAT SCALES ARE NEEDED FOR CALIBRATION?

Answer 20

1. Eye piece gratitude - small scale placed in the microscope write piece.
2. Stage micrometer - accurately drawn scale of known dimensions, engraved on the microscope slide.