General Zoology Laboratory - Module 1: Parts of the Microscope

Flashcards covering the history, parts, functions, and magnification calculations of the compound microscope, as well as staining techniques for cheek and onion cells.

Hans and Zacharrias Janssen

Dutch scientists who invented the microscope in 1590.

Robert Hooke

Scientist who published his discovery of the cell using the microscope.

Leuwenhoek

Scientist who created powerful lenses in the 16th century that led to the discovery of bacteria.

Compound microscope

The most common type of microscope that uses two or more lenses.

Eyepiece

The part where the viewer looks through to see the specimen, usually containing a $10X$ magnification.

Objectives

Parts responsible for the image of the specimen which vary based on magnification; include Scanning ($4x$), Low power ($10x$), High power ($40x$), and Oil immersion ($100x$).

Scanning Objective

An objective lens with a magnification of $4x$.

Low Power Objective

An objective lens with a magnification of $10x$.

High Power Objective

An objective lens with a magnification of $40x$; also referred to as high dry objective.

Oil Immersion Objective

An objective lens with a magnification of $100x$.

Revolving Nose Piece

The part of the microscope that allows the user to switch between different objectives.

Light Source

Provides illumination; older microscopes used mirrors to reflect light from an external source up through the bottom of the stage.

Coarse Adjustment

The knob used to bring the specimen into general focus.

Condenser

Filters the amount of light going to the bottom of the stage.

Fine Adjustment

Increases the detail of the specimen; it is the ONLY adjustment knob that should be used under high power.

Stage Clip

A mechanism that holds the glass slide in place.

Stage

The platform that holds the stage clip and the specimen slide.

Base

The bottom part that supports the entire microscope.

Methylene blue

A dye used to stain cheek cells so that they can be seen under the microscope.

Iodine

A substance used to stain onion membranes and cheek cells to make structures like the nucleus and cell membrane visible.

Total Magnification Formula

$$\text{Eyepiece} \times \text{Objective} = \text{Total Magnification}$$

Total Magnification (Oil Immersion)

A total magnification of $1000x$ ($10X \text{ eyepiece} \times 100x \text{ objective}$).

Total Magnification (High Power)

A total magnification of $400x$ ($10X \text{ eyepiece} \times 40x \text{ objective}$).

Total Magnification (Scanning)

A total magnification of $40x$ ($10X \text{ eyepiece} \times 4x \text{ objective}$).

Total Magnification (Low Power)

A total magnification of $100x$ ($10X \text{ eyepiece} \times 10x \text{ objective}$).

Red Ring

The color ring on an objective lens signifying $4x$ or $5x$ magnification.

Yellow Ring

The color ring on an objective lens signifying $10x$ magnification.

Green Ring

The color ring on an objective lens signifying $20x$ magnification.

Blue Ring

The color ring on an objective lens signifying $40x$, $50x$, or $60x$ magnification.

White Ring

The color ring on an objective lens signifying $100x$ magnification.

Stereo Microscope

A microscope that mimics the natural offset of the eye by using two compound microscopes joined side-by-side with an offset.