Micro Test 1 : Chapter 2 Microscopy And Visulizing Cells

Question 1

Visible light

Answer 1

Electromagnetic energy waves constrained with certain range of wavelengths that we can see

Question 2

Reflection

Answer 2

Light bouncing off a surface

Question 3

Absorbance

Answer 3

When energy is captured by the reflecting material

Question 4

Transmittance

Answer 4

The process of light traveling through a material

Question 5

Transparency and opacity

Answer 5

The relative ability and inability to transmit light

Question 6

Interference

Answer 6

When light waves interact with each other

Question 7

Diffraction

Answer 7

The bending or scattering of light when it strikes a small object or passes through an opening

Question 8

Lenses how they work

Answer 8

Light waves can change speed when entering a new medium which can cause them to change direction

Question 9

Refractive index

Answer 9

The degree to which a medium changed the speed of light

Question 10

Lenses

Answer 10

Lens like prism - bends

Convex lense - bends light inward to a cone where light rays meet at a focal point

Concave lens - scatters light from a focal point outwards

Light is focused before entering eye where it is focused again resulting in a enlarged image

Question 11

Florescence

Answer 11

when a substance absorbs light of one higher wavelength and uses that energy to emit light at another lower wavelength

Question 12

Magnification

Answer 12

Ability of a lens to enlarge the image

Question 13

Resolution

Answer 13

The ability to tell two different objects apart when views through a lens

Question 14

Contrast

Answer 14

The ability to differentiate an object from the background

Question 15

Microscopes types

Answer 15

Simple (single lens)
Or
Compound (multiple lenses)

Question 16

Most Common Microscope

Answer 16

Bright field
Has a lightened background with most light being directed at the specimen

Question 17

Darkfeild microscope

Answer 17

Provides a dark background and lights up specimens

Question 18

Florescence microscopy

Answer 18

Utilizes fluorescent molecules (fluorochromes) to tag structures

Light contains a excitatory wavelength lights up fluorochromes

Question 19

Confocal microscopy

Answer 19

Similar to fluorescent microscopy uses fluorochromes and laser to illuminate them

Creates 3D images

Question 20

Electron microscopy

Answer 20

Uses electron beam to illuminate images

Allows to see much smaller molecules

TEM (tunneling) penetrates to show internal structure

SEM (scanning) renders 3D images

Question 21

Scanning Probe microscopy

Answer 21

Uses very fine and sharp prone that passes over object

Visualize 100,000,000x mag visualize molecules and larger atoms

Question 22

Bacteria seen with…

Answer 22

Bright field microscope through wet or heat fixed mount

Stains are often used to see transparent cells

Question 23

Stains

Answer 23

Either basic or acidic (opposites attract)

Basic stain + charge called positive stain attarcts to - cells

Acidic stain - charge called negative stain attracts to + cells

Question 24

Simple stain

Answer 24

One Dyes all cells in a sample the same color

Question 25

Differential stain

Answer 25

Uses two or more dyes for diff cells to see their unique properties

Question 26

Gram stain

Answer 26

A differential stain that is one of the most common staining techniques used

Question 27

Gram stain invented by…

Answer 27

Hans Cristian Gram 1884

Distinguishes between bacteria with tow diff cell wall motifs

Question 28

Gram negative bacteria def

Answer 28

Bacterium loses the primary stain in the presence of decolorizer

Question 29

Gram pos bacterium def

Answer 29

Retains primary stain in the presence of decolorizer

Question 30

Primary stain

Answer 30

Crystal violet used with a mordant or hardening agent (grams iodine) causes primary stain to stick to the bacterial wall

Question 31

Decolorizer

Answer 31

Ethanol or ethanol & acetone mix

Question 32

Secondary stain

Answer 32

Or counter stain is safranin

Question 33

Bacterial walls

Answer 33

Thick or gram positive bacteria has thick walls made of peptidoglycan

Thin walls lose color and become transparent (light pink because safranin)

Question 34

Acid fast stain

Answer 34

Used for bacteria with waxy hydrophobic cell walls like mycobacterium

AFB+ one that retains the primary stain with presence of an acidified decolorizor (red)

AFB- one loses primary stain or acidic decolorizer and use of secondary stain methane blue (light blue)

Question 35

Capsule stain

Answer 35

Some cells secrete protective gel around them called glycocalyx
With capsule stain we stain the surrounding background

Question 36

Virulence factor

Answer 36

Ability to form a capsule around bacterial material aids in bacterium causing disease

Question 37

Endospores

Answer 37

Some bacteria had ability to package up material into a hard durable endospore that is resistance to heat and chemicals can survive a long time and can regerminate

Question 38

Flagella stain

Answer 38

Some bacteria archaea and eukaryotes have tail like structures too thin to see with optimal scope

Layers of dye added to thicken flangella to be able to see

Question 39

Morphology

Answer 39

Cell shape including appendages

Question 40

Aggregate

Answer 40

How members of a colonial colony associate with each other