Theories

"SPONTANEOUS GENERATION" -or- "ABIOGENESIS"
--- living things arising from nonliving things
--- abolised in 1660 by Francesco Redi

"BIOGENESIS"
--- living things arising from pre-existing living things
--- term coined in 1870 by Thomas Henry Huxley

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Chemical Basis of Life

"ATOM" indivisible particle (parts: nucleus, protons, neutrons, electrons) (Et. Greek 'atomos' indivisible)

"ELEMENT" substance made up of only one kind of atoma

"COMPOUND" substance made up of two or more different elements

"MOLECULE" smallest particle of a compound

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Hierchical Organization / Structural Levels

• sub-atomic particles: protons, neutrons, electrons
• atom: indivisible particle (parts: nucleus, protons, neutrons, electrons) (Et. Greek 'atomos' indivisible)
• molecule: smallest particle of a compound
• organelle: membrane-bound compartments within cell
• cell: basic unit of life
• tissue: group of same kind of cells
• organ: group of tissues acting together to perform specific functions
• organ system: group of organs interacting as structural units with integrated functions
• multicellular organism: living entity
• population: localized group of organisms of the same species
• community: group of interacting populations
• ecosystem: system of interdependent communities and environment
• biospehere: world of life

"MICRON" µ -or- "MICROMETER" µm
--- basic unit used in measuring microscopic objects
--- conversion: 1mm = 1,000µ

"FIELD OF VISION"
--- microscopic field in which specimens are seen

"LINEAR MAGNIFICATION"
--- aligning of objective lens with ocular piece

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Diameter Method
--- measure diamter of field of vision
--- use ruler

~ the LPO's field of vision (FOV) is usually 1.1mm to 1.5mm in diameter ~

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Computation Method
--- aim: get FOV of HPO
--- given:

• FOV(LPO) in µ
• ratio of magnification (ROM) of objectives given: ROM = LPO/HPO

example:

given
FOV(LPO) = 1.1mm -convert to- 1,100µ
LPO 10x magnification; HPO 50x magnification

equation
ROM = LPO/HPO
ROM x FOV(LPO) = (FOV)(HPO)

solution
ROM = 10/50 = 1/5
1/5 x 1,100 = 220

final answer
field of vision of HPO is 220µ.

"MICROSCOPY"
the use of miscoscopes

"MICROSCOPE"
optical instrument used to enlarge (the appearance of) small objects

"MAGNIFICATION"
how big the object appears -or-
number of times an object's appearance is reduced or enlarged

"RESOLUTION"
how clear the magnified image is -or-
smallest distance (d) between two points resolvable as separate points when viewed through lenses

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Proponents (Scientists)

Zacharias Jansen (1590)
--- a Dutch maker of spectacles
--- first compound microscope

Antony van Leeuwenhoek
--- first to make extensive use of microscope
--- used simple microscope

Robert Hooke
--- improved on compound microscope
--- known for microscopic studies of biological specimens

Ernst Abbe
--- improved on microscopic lenses

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Types

Compound Microscope
--- uses two separate lens systems

Simple Microscope
--- uses only one lens (approx. max. magnification 300x-500x)
--- hard to use because of problems with source of light

Transmission Electron Microscope
--- useful for viewing dead specimens (sepcimens have to be spliced and stained)
--- uses electrons as source of light
--- up to 200,000x to 1,000,000x magnification

Phase-Contrast Microscope
--- useful for viewing live specimens (transparent specimens, without staining, can be viewed)

Polarizing Microscope
--- useful for differentiating between different types of materials embedded in substances

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Parts

(drawing coming soon)

Lenses
--- Ocular Piece / Eyepiece (5x-10x magnification)
--- Objective

• LPO (Low-powered objective) (approx. 10x magnification)
• HPO (High-powered objective) (approx. 40x magnification)
• OIO (Oil immersion objective) (approx. 90x magnification)

Body Tube

Revolving Nosepiece (holds objectives)

Stage (holds specimen)

Condenser (filters light)

Mirror (light source)

Course/Fine Adjustment Knobs (moves the body tube closer to/farther from specimen)

Base