BIOL 110 - Quiz 1 - microscopy lab & 8/27 lecture

Magnify

Making specimens appear larger

Resolution

Distinguish two objects that are close together as being two separate objects

Contrast

Different parts of an object absorb or transmit different amounts of light

Diopter Ring

Tool on eyepiece that allows you to precisely adjust the sharpness of the image for each of your EYES

Eyepiece magnification is 10x

Nosepiece

Has four objective lenses that can be rotated to change objectives

Objective

Each objective has a different magnification: the shortest magnifies 4 times, the next 10 times, the next 40 times and the longest 100 times.

Total magnification

The product of the eyepiece and objective lens magnification

Mechanical stage

Where a slide is placed

Caliper

Tool on mechanical stage that holds a slide in place

Stage control

Moves the slide

The lower knob moves the slide left and right

The upper knob moves the slide towards or away from you

Focusing knobs

2 types: coarse and fine focus knobs

Coarse focus knobs

Outer/larger ring, closer to middle of microscope

Should only be used with 4x and 10x objectives

Moves the stage up or down quite a distance to permit focusing

Fine focus knobs

Can be used for all types of objectives (40x and 100x can only use this)

The fine focus moves the stage vertically only a small distance

Inner/smaller ring, away from the middle of the microscope

Condensor

Holds an iris diaphragm

Iris diaphragm

Controls contrast

Opened = more light, closed = less light

When using the higher magnification objectives, open diaphragm to allow sufficient light to see objects clearly

At lower magnification, contrast is an issue, so close the diagraph to increase contrast

The diaphragm is opened and closed by way of a lever located on the front of the condenser.

Switch

Located on the right side of the microscope

Activates the light source

Light intensity control knob

Increases/decreases light brightness

Atom vs cell

Atom - basic unit of matter

Cell - basic unit of life

Cell size

Eukaryotic cells > prokaryotic cells

Prokaryotic cells > viruses

Viruses > macromolecules

Macromolecules > single atom

Atoms are the building blocks of life

Compound microscope

A type of light microscope that uses many lenses (4 objectives & eyepiece)

Bigger specimens use _____ objectives.

smaller

Total magnification is ______ with apparent pointer width

Inverse