Unit C: Section 1.0 Flashcards

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1
Q

Who invented the microscope?

A

Hans and Zacharias Janssen

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2
Q

What was the first compound microscope comprised of?

A

Used 2 lenses, an eyepiece and an objective lens

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3
Q

What is a compound microscope?

A

Using more than one lens to magnify an object

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4
Q

What was the magnifying power of the Janssens microscope?

A

20X

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5
Q

Who created the second microscope ever?

A

Robert Hooke

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6
Q

What was different between the Janssens and Hooke microscope?

A

The Hooke microscope used 3 lenses and the Janssens microscope used 2 lenses

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7
Q

Describe how the Hooke microscope worked

A

Used three lenses. Illuminated by a beam of light concentrated on a specimen by passing the light through a water-filled flask

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8
Q

What was the added lense in the Hooke microscope?

A

A “field lens” that passes light rays in a straight. Allowed for better conservation of light

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9
Q

What did Robert Hooke publish?

A

A micrographia containing 38 illustrations of plant, animal, and non-living objects that he viewed through a microscope

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10
Q

What were the unusual properties of cork?

A
  • Lightweight
  • Could float on water
  • Firm,
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11
Q

What were the air pockets in corks referred to as?

A

Cells because they resembled the places that monks lived in

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12
Q

What did the cork consist of?

A

Air pockets surrounded by a thin mesh of fibre. They were actually remnants of living cells

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13
Q

Who created the single lens microscope?

A

Antonio van Leeuwenhoek

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14
Q

What did the single lens microscope resemble?

A

A magnifying glass

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15
Q

What did Antonio van Leeuwenhoek see under his microscope?

A

Movement of single cells known as bacteria, sperm, and single cell protoza’s

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16
Q

How were the single cells observed by Leeuwenhoek described as?

A

Animalcules. Individual Free living cells surviving as independant systems

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17
Q

What were the sizes of Leeuwenhoek’s microscopes?

A

Small, about the size of a palm and held directly to the eye

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18
Q

What was the magnification of Leeuwenhoek’s microscopes?

A

250X

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19
Q

Why did Leeuwenhoek have lots of success?

A

They produced clear images without a halo light

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20
Q

What caused the blurry images within a microscope?

A

-Result of light being scattered as it passed through the different lenses

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21
Q

What did achromatic lenses do?

A
  • Controlled the halo of light

- Improve detail

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22
Q

What are the parts of the microscope?

A
  • Eyepiece/ocular lens
  • Coarse adjustment knob
  • Fine adjustment know
  • Revolving nosepiece
  • Objective lenses
  • Stage
  • Stage clips
  • Diaphragm
  • Lamp or mirror
  • Arm
  • Base
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23
Q

What was the function of the eyepiece?

A

To look through or observe specimen

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24
Q

What was the function of the Coarse adjustment knob?

A

To move stage up or down

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25
Q

What was the function of the Fine adjustment knob?

A

To bring the object into a sharper focus and produce a clear sharp image

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26
Q

What was the function of the Revolving nosepiece?

A

To change magnification lens

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27
Q

What is the function of the objective lens?

A

To increase magnification

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28
Q

What was the function of the Stage?

A

To hold/support specimen

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29
Q

What was the function of the Stage Clips?

A

To hold slide in place

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30
Q

What was the function of the Diaphragm?

A

Adjust diameter of the opening

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31
Q

What was the function of the Lamp or Mirror?

A

To direct light towards a specimen

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32
Q

What was the function of the arm and base?

A

To provide support when holding

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33
Q

What is Spontaneous generation?

A

The idea that life could emerge spontaneously from non-living matter

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34
Q

How did they believe that you could make mice?

A

By combing wheat and sweaty underwear for 21 days

35
Q

How did Francesco Redi attempt to disprove spontaneous generation?

A

He exposed meat in varied conditions. Only the meat that was fully exposed did the flys lay maggots on

36
Q

How did John Needham try and prove that Spontaneous Generation existed?

A

He boiled chicken broth put it in a flask and sealed it. Because he boiled he believed that all the microorganisms were dead but the broth still went bad.

37
Q

What did Needham suggest?

A

There was a life force that produced spontaneous generation

38
Q

What was stated against Needham’s observations?

A

That his broth wasn’t sealed off and that there is bacteria in the air

39
Q

How did Louis Pasteur disprove spontaneous generation?

A

He boiled broth and put it in an ‘s’ shaped flask so that air could reach it but the bacteria got caught in the bend of the ‘s’

40
Q

Who discovered the nucleus?

A

Robert Brown

41
Q

What was the nucleus described as?

A

Opaque granular spots within the cell

42
Q

What did M.J Schleiden state about the nucleus?

A

It was the structure responsible for the development of the cell

43
Q

What did the cell theory state?

A
  • All living things are made up of one or more cells
  • All living functions take place in the cell, making them the smallest unit of life
  • All cells are produced from preexisting cells through the process of cell division
44
Q

What are neither living or non-living cells?

A

Subcellular cells like viruses and prions

45
Q

What do light microscopes use to magnify cells?

A

One or more curved lenses and a light source

46
Q

What is the maximum magnification a light microscope can have?

A

1000-2000X

47
Q

What are the 3 factors that affect what can be seen through a microscope?

A
  • Magnification
  • Contrast
  • Resolution
48
Q

What is brightfield?

A

When light passes directly through cells and all the cells appear colourless

49
Q

What did scientists create to improve the contrast of the cell?

A

They created stains

50
Q

How did stains work?

A

Particular stains attached to particular parts of the cell improving the contrast between the structures

51
Q

What is a disadvantage of staining cells?

A

It kills the cells so it is not possible to see living cells

52
Q

What is resolution?

A

The ability to distinguish between two structures that are very close together

53
Q

How small can the human eye distinguish objects?

A

0.1 mm or larger

54
Q

Why is the efficiency of a microscope limited?

A

Because as light is focused into small diameters it become blurred

55
Q

What is the limit of resolution in a standard light microscope?

A

0.2 microns

56
Q

Why do some organelles appear lighter or darker in images?

A

Because they change the speed and direction of light more than others can

57
Q

How do fluorescence Microscopes work?

A

They use fluorescent substances to attach to molecules in tissue. When subjected to different types of lights they would glow

58
Q

How does a confocal microscope work?

A

A laser concentrates light onto a specimen. Then the light is concentrated through a confocal pinhole. It reaches an electronic detector that converts light into an image

59
Q

How does a confocal microscope produce a clearer image?

A

It only allows light that is in focus to pass through the confocal pinhole

60
Q

Which microscope can produce 3D images?

A

Confocal microscopes

61
Q

Why can a Confocal microscope produce?

A

Because every image formed is a very thin section of the specimen. Each image is stored in a computer and every image can be combines

62
Q

What is a positive to green fluorescent protein?

A

It does not kill the cell when it stains it

63
Q

What are the 3 types of electron microscopy?

A
  • Electron Microsope
  • Transmission Electron Microscope
  • Scanning Electron Microscope
64
Q

How does an electron microscope work?

A

Uses a beam of electrons instead of light and is able to produce images in fine detail

65
Q

How is an image formed in an electron microscope?

A

The image is formed by the absorption or scattering of the electron beam because of electron-dense material that does not let electrons pass through

66
Q

How is focussing done on an electron microscope?

A

By adjusting of the electromagnets

67
Q

How does a Transmission Electron Microscope work?

A

Passes electrons through a very thin section of a cell. The electrons that pass through fall on a fluorescent screen

68
Q

What is the magnification and resolution of TEM?

A

1 500 000X

2.5 nm

69
Q

How does a Scanning Electron Microscope work?

A
  • Specimens are covered with electron-dense material like gold which reflects electrons
  • Electrons bouncing off the surface are picked up by the sensor and a three-dimensional image is formed
70
Q

What is the magnification and Resolution of a SEM?

A

300 000X

20nm

71
Q

What are micrographs?

A

Photographs taken by either scanning or transmission electron microscopes

72
Q

What is a drawback of the TEM?

A
  • Difficulty building up a three-dimensional image
  • All specimens are dead
  • Must be operated in a vacuum
73
Q

What are the smallest units of measurement in ascending order?

A

Micrometer/Micron
Nanometer
Angstrom

74
Q

How many microns or micrometres are in 1 millimetre?

A

1000

75
Q

How many nanometers are in 1 micrometre/micron 1000

A

1000

76
Q

What types of microscopes allow scientists to view images of molecules?

A

The Scanning Tunnelling microscope and the Atomic Force Microscope

77
Q

What type of system are cells?

A

Open systems because they exchange and matter with their environment

78
Q

How do cells communicate with each other?

A
  • Messenger molecules from cells travel through the bloodstream and attach to receptor molecules on the target cell.
  • The receptor cells trigger a chain reaction to carry the message into the proper place inside the cell
79
Q

What does X-Ray crystallography do?

A

Analyzes patterns of molecules to help scientists to understand what molecules look like

80
Q

What is the source of a light microscope vs an electron microscope?

A

Lamp or laser vs Electron Gun

81
Q

What is the source of a radiation on a light microscope vs an electron microscope?

A

UV or Visible light vs Electron Beam

82
Q

What is the lense of a light microscope vs an electron microscope?

A

Curved glass surface vs Electromagnets

83
Q

What is the receiver of a light microscope vs an electron microscope?

A

Eye or digital image vs Fluorescent screen or digital image

84
Q

What is the focus of a light microscope vs an electron microscope?

A

Up and down movement of the lenses vs adjustment of the magnetic field