2.1 MICROSCOPY

Question 1

What is the chronological order of the creators of the Cell Theory?

Answer 1

Odiena
Hooke
Leeuwanhoek
Dumortier
Brown
Schwann
Remak
Pasteur

Question 2

What did Odiena do?

Answer 2

Wrote “The Fly’s Eye”

Question 3

What did Hooke do?

Answer 3

Wrote “Micrographia”, observed cell walls in a cork

Question 4

What was Leeuwanhoek known for?

Answer 4

“The Father Of Microscopy”, high power lenses

Question 5

What was Dumortier known for?

Answer 5

Cell theory in plants and cell division in plants of older cells (not animals due to religion)

Question 6

What was Brown known for?

Answer 6

“Brownian Motion”, first to use word Nucleus

Question 7

What was Schwann known for?

Answer 7

Extension of cell theory to animals, “Schwann Cells”, and metabolism/pepsin

Question 8

What was Remak known for?

Answer 8

Cell division - cells come from pre-existing cells, denied full professor status due to being a Jew

Question 9

What was Pasteur known for?

Answer 9

vaccination, fermentation, pasteurisation, allowed full acceptance of cell theory

Question 10

How did Fermentation prove the cell theory?

Answer 10

When liquid was in a containing with a swan neck, and heated, there was no bacteria present.
When the swan neck was removed and heat applied, there was bacteria present.
With a swan neck, the container was tipped to allow air flow towards the liquid (with heat), bacteria present.
- Only when a stable flow of air containing bacteria particles did the liquid ferment (swan neck restricted this).

Question 11

What are the main components of the cell theory?

Answer 11

1. All organisms are composed of 1+ living cells
2. Cells are the basic unit of structure
3. All cells arise from pre-existing cells

Question 12

What are the main features of a Light Microscope?

Answer 12

• increased resolution
• two lenses to reduce CHROMATIC ABERRATION
• produce light micrographs
• magnification of x1500/x2000
• theoretical resolution limit of 0.2 micrometers / 200 nanometers

Question 13

What is a Dry Mount?

Answer 13

Solid specimens are sectioned

Question 14

What is a Wet Mount?

Answer 14

Specimen is suspended in liquid, with the cover slip placed at an angle (usually aquatic samples)

Question 15

What is a Squash Slide?

Answer 15

Wet Mount is first prepared, lens tissue used to gently press down the cover slip

Question 15

What is a Squash Slide?

Answer 15

Wet Mount is first prepared, lens tissue used to gently press down the cover slip

Question 16

What is a Smear Slide?

Answer 16

the edge of the slide is used to smear the sample

Question 17

Why is the cover slip used at an angle?

Answer 17

To reduce air bubbles

Question 18

Why does the Refractive Medium in a wet mount have to be similar to the glass?

Answer 18

To prevent diffraction between the liquid and the glass and thus preventing image distortion.

Question 19

Why are some specimens stained?

Answer 19

To increase the contrast of the cell components - take up different stains at different rates.

Question 20

What studies is staining used in?

Answer 20

Histology (tissues), Histopathology (diseases in tissues), haematology (blood), cytopathology (cells), needed in “bright field microscopy”

Question 21

What is Single Staining?

Answer 21

• a slide preparation
• Crystal Violet/ Methylene Blue are positively charged, bind to chemicals in the cytoplasm.
  As the DNA in nucleus is negatively charged

Question 22

What is Differential Staining?

Answer 22

• 2+ stains to increase contrast
• Gram Staining (with a slime layer = purple, without = pink) in bacteria
• Haematoxylin/ eosin (red/pink) are used in histology

Question 23

What is the criteria of Scientific drawings?

Answer 23

• sharp pencil
• half space at lease
• clear and continuous lines
• label lines can’t cross
• annotations
• scale
• tittle
• no shading
• proportions need to be accurate