Midterm

Microscope Base

Foundation; used for carrying the microscope.

Light Source

Located in the base; provides illumination for viewing specimens.

Stage

Supports the slide on which specimens are placed for observation.

Condenser

Collects and directs light onto the specimen.

Diaphragm

Controls the amount of light that reaches the specimen.

Objective Lenses

Located on the rotating nosepiece; used to magnify the specimen.

Coarse Focus Knob

Large knob used for coarse focusing the microscope image.

Fine Focus Knob

Smaller knob used for fine focusing the microscope image.

Resolution

Clarity and detail of an image; smallest distance between two structures still seen as separate.

Micrometer (µm)

One millionth of a meter; unit used to measure microbes.

Nanometer (nm)

One billionth of a meter; used for measuring viruses.

Millimeter (mm)

One thousandth of a meter; used for measuring helminths.

Gram Staining Order

The sequence: Crystal violet → Gram’s iodine → Alcohol → Safranin.

Gram-positive Appearance

Stains purple after the Gram-staining process.

Gram-negative Appearance

Stains pink/red after the Gram-staining process.

Bacillus Shape

Rod-shaped bacterial morphology.

Coccus Shape

Spherical bacterial morphology.

Strepto- Arrangement

Bacterial arrangement in chains.

Diplo- Arrangement

Bacterial arrangement in pairs.

Staphylococcus

Bacterial arrangement in clusters.

Trematodes

Flukes; include species like Clonorchis and Schistosoma.

Cestodes

Tapeworms; include species like Taenia.

Nematodes

Roundworms; include species like Ascaris and Enterobius.

Giardia lamblia

Causes Giardiasis; diagnosed by trophozoites or cysts in stool.

Trichomonas vaginalis

Causes Trichomoniasis; diagnosed through microscopic examination of discharge.

Trypanosoma brucei

Causes African sleeping sickness; transmitted by the tsetse fly.

Entamoeba histolytica

Causes Amoebiasis; transmitted via fecal-oral route.

Plasmodium spp.

Causes Malaria; transmitted by female Anopheles mosquitoes.

Aspergillus

Fungi associated with aspergillosis; varies in color and structure.

Penicillium

Fungi used in antibiotic production; associated with cheese fermentation.

Acid-Fast Stain

Used for organisms with a waxy cell wall containing mycolic acid.

Endospore Stain

Identifies dormant, resistant endospores in bacteria.

Streak Plate Technique

A method for isolating bacteria by decreasing cell density on an agar plate.

CFU (Colony Forming Unit)

A measure used to estimate the number of viable microorganisms in a sample.