Mastering the Light Microscope

Vocabulary and key concepts from the lecture on light microscopy, including parts of the microscope, handling safety, magnification calculations, and the history of cell discovery.

Magnification

The process of making an object appear larger than it is.

Microscope

An instrument used to see objects that are too small for the naked eye.

Objective

The lens nearest to the object being examined.

Specimen

A sample of a substance or organism used for medical or scientific study.

Biological Hierarchy

The levels of organization from largest to smallest: Biosphere, Ecosystem, Community, Organism, System, Organ, Tissue, and Cell.

Light Microscope

An instrument that uses focused visible light and glass lenses to magnify images of small subjects, allowing the observation of living cells in real-time.

Stage

The platform where the microscope slide is placed for observation.

Eyepiece (Ocular Lens)

The part of the microscope that you look through; it typically has a magnification of $10 \times$.

Objective Lens

The lens located on the nosepiece nearest to the specimen; common powers include low power and high power.

Coarse Focus

The knob used first to bring the image into view by making large adjustments.

Fine Focus

The knob used for sharp, detailed focusing; it is the only focus knob that should be used on high power to prevent breaking the slide.

Two-Hand Hold

The safe handling procedure of carrying the microscope with one hand on the arm and the other under the base.

Lens Paper

The only material that should be used to clean the glass lenses of a microscope to avoid damage from oils or scratches.

Total Magnification

The product of the ocular lens magnification multiplied by the objective lens magnification (e.g., $10 \times$ eyepiece multiplied by a $40 \times$ objective equals $400 \times$).

Red Blood Cells

Tiny, reddish discs that look like donuts without holes when viewed under a microscope.

White Blood Cells

Cells that are larger and rarer than red blood cells, often containing dark purple centers called nuclei.

Plant Cells

Cells characterized by a rigid, fixed 'box-like' shape due to a cell wall and often containing green dots called chloroplasts.

Animal Cells

Cells that typically look irregular or rounded and lack a cell wall and chloroplasts.

Nosepiece

The rotating part of the microscope that holds the objective lenses.

Arm

The part that connects the tube to the base and is used as a handle for carrying the microscope.

Base

The bottom support of the microscope.

Robert Hooke

The scientist who, in $1665$, discovered and named 'cells' after observing a thin slice of cork.

Antonie van Leeuwenhoek

The scientist who in the $1670s$ first observed living microbes and tiny organisms in water.

Electron Microscope

A powerful microscope that uses beams of electrons to achieve magnification up to $10,000,000 \times$, though it can only view non-living, vacuum-sealed items.

Diaphragm

A component under the stage that controls the amount of light passing through the slide to adjust contrast.

Resolution

A measure of how clear or sharp an image is.

Chloroplasts

Organelles appearing as green dots in plant cells that are responsible for photosynthesis.