Microbiology Lab Midterm Review

Liver Fluke

A type of trematode that infects the liver of various mammals, including humans.

Scolex

The anterior end of a tapeworm, having suckers or hooks for attachment to the host's intestine.

Gram negative bacteria

Bacteria that do not retain the crystal violet stain in the Gram staining procedure, appearing pink under the microscope.

Endospore stain

A differential staining technique used to detect the presence of endospores in bacterial cells.

Endospore producers

Bacteria capable of forming endospores as a protective mechanism.

Slant culture characteristics

The appearance of bacterial growth on the slanted surface of a solid culture medium.

Mannitol Salt agar

A selective and differential culture medium used to isolate and identify staphylococci.

McConkey Agar

A selective and differential culture medium used for the isolation of enteric gram-negative bacteria.

Mycelium

The vegetative part of a fungus, consisting of a network of hyphae.

Rhizopus

A genus of common saprophytic fungi, known for their black bread mold.

Conidiophore

Specialized fungal hypha that produces conidia (asexual spores).

Basidiospore

A sexually produced fungal spore borne on a basidium.

Ascospore

A spore contained in an ascus or derived from it, produced by ascomycete fungi.

Dimorphism

The ability of some fungi to exist in two different forms, typically as yeast and hyphae.

Trophozoite

The motile feeding stage of protozoa.

Pseudopod

Temporary protrusion of the cytoplasm of a cell, serving for movement and feeding in some protozoa.

Beef Tapeworm

Taenia saginata, a tapeworm species transmitted through undercooked beef.

Parfocal

Describing microscopes where the specimen remains nearly in focus when the objective lens is changed.

Cationic stains

Stains with positively charged chromophores, used to colorize negatively charged bacterial cell walls.

Gram stain

A differential staining technique that divides bacteria into Gram-positive and Gram-negative groups.

Capsule stain

A staining technique used to visualize the protective capsules surrounding certain bacteria.

Anaerobic bacteria

Bacteria that can survive and grow in the absence of oxygen.

Sporangiospore

A type of asexual spore produced by sporangium in fungi.

Zygospore

A thick-walled sexual spore formed from the fusion of compatible gametangia in fungi.

Cyst

A dormant and resistant cell formed by some protozoa as a protective measure.

Cilia

Microscopic, hair-like structures on the surface of some cells, used for movement or sensing.

Flagella

Long, whip-like appendages that provide motility to certain cells, such as bacteria and sperm.

Entamoeba histolytica

A protozoan parasite causing amoebic dysentery and other intestinal infections.

Balantidium coli

A parasitic ciliate causing the disease balantidiasis, primarily affecting the intestine.

Giardia lamblia

A flagellated parasite causing giardiasis, a diarrheal illness.

Trypanosoma gambiense

A parasitic flagellated protozoan causing African trypanosomiasis (sleeping sickness).

Plasmodium vivax

A protozoan parasite causing malaria in humans.

Phylum Platyhelminthes

A phylum of flatworms, including tapeworms and flukes.

Phylum Nematoda

A phylum of roundworms, including many parasitic species.

Cestoda

A class of parasitic flatworms, including tapeworms.

Trematoda

A class of parasitic flatworms, including flukes.

Blood fluke

A type of trematode that infects the blood vessels of the host.

Monoecious

Having both male and female reproductive organs in the same individual.

Dioecious

Having male and female reproductive organs in separate individuals of the same species.

Pork tapeworm

Taenia solium, a tapeworm species transmitted through undercooked pork.

Pin worm

Enterobius vermicularis, a parasitic nematode causing enterobiasis in humans.

Proglottids

Segments of a tapeworm body, containing reproductive organs and eventually detaching from the main body.

Magnification

The increase in apparent size of an object under observation, achieved by lenses or microscope.

Resolution

The ability to distinguish two separate points in an image, often limited by the wavelength of light used.

Working Distance

The distance between the objective lens and the specimen being observed.

Field of view

The area visible through the microscope's lenses at a specific magnification.

Aseptic technique

Procedures used to prevent contamination of cultures or sterile materials.

Streak Plate method

A technique to isolate pure bacterial colonies for study.

Hanging drop method

A method for observing living, unstained microorganisms using a special slide and coverslip.

Smear

A thin layer of a specimen, such as bacteria, spread on a microscope slide for staining and observation.

Heat fixing

Passing a specimen-bearing slide through a flame to kill the organisms and affix them to the slide.

Simple stain

A staining technique using a single dye to color the entire bacterial cell.

Shapes of bacteria

The various forms of bacteria, such as cocci (spherical), bacilli (rod-shaped), and spirilla (spiral).

Anionic stains

Stains with negatively charged chromophores, used to colorize positively charged bacterial cell walls.

Gram positive bacteria

Bacteria that retain the crystal violet stain in the Gram staining procedure, appearing purple under the microscope.

Peptidoglycan

A polymer comprising sugars and amino acids, forming a mesh-like layer outside the plasma membrane of bacteria.

Acid fast stain

A differential staining technique used to identify acid-fast bacteria, such as Mycobacterium species.

Acid fast bacteria

Bacteria that resist decolorization by acid-alcohol after being stained with carbol fuchsin, appearing red under the microscope.

Non-acid fast bacteria

Bacteria that are easily decolorized by acid-alcohol after being stained with carbol fuchsin, appearing blue under the microscope.

Negative stain

A staining technique that colors the background, leaving the bacteria unstained and transparent.

Colony/Cultural characteristics

The observable traits of bacterial colonies grown on solid media, including color, shape, and texture.

Margin of colony

The edge of a bacterial colony, which can be entire, undulate, lobate, or filamentous.

TFTC

Too few to count, indicating a very low bacterial count in a sample.

TNTC

Too numerous to count, indicating a very high bacterial count in a sample.

Selective Media

Culture media designed to favor the growth of specific microorganisms while inhibiting others.

Differential Media

Culture media that allows the differentiation of microorganisms based on their growth and metabolic characteristics.

Blood Agar

A general-purpose enriched medium used to cultivate fastidious microorganisms.

Effect of UV on bacteria

The damaging effect of ultraviolet (UV) radiation on bacterial DNA, leading to mutations and cell death.

Hypha

A thread-like structure in fungi, consisting of a chain of connected cells.

Yeast

Single-celled fungi that reproduce asexually by budding or fission.

Penicillium

A genus of mold fungi, some species of which produce the antibiotic penicillin.