BIO 220: Final Exam Review - Night Term Fall 2024

Dark image with bright background; most widely used.

Bright-field microscope (light microscope)

Bright image, dark background

Dark-field microscope

Organism stained with fluorochromes and fluorescent light passes through object seen on dark-field

Fluorescence microscope

Electron beams are forced through a thin specimen. (100,000,000x)

Electron microscope

The bending or change in the angle of the light ray as it passes through a medium such as a lens.

Refraction

• A small volume of sample is pipetted onto the surface of the plate using a sterile spreading tool to spread the sample around evenly.

spread plate technique

Sample is diluted serially into cooled, but still liquid agar tubes, poured into sterile Petri dishes and allowed to solidify.

pour plate method

• A small droplet of culture or sample is spread across the surface of a medium with an inoculating loop.

streak plate method

Allow multiple types of microorganisms to grow, but display visible differences between colonies.

differential media

Contains on or more agents that inhibit the growth of certain microbes.

Example: salts and certain dyes inhibit gram-positive growth, but don't stop gram- negative.

Selective media

Contains complex organic nutrients (blood, serum, hemoglobin) that fastidious bacteria require for growth.

Enriched media

Contains ingredients of unknown chemical composition, which is good because it can grow many types of bacteria.

Example: Agar, soy broth, nutrient broth, silica gel.

Complex media

Using alcohol and formaldehyde for fixation.

Chemical fixing

Heating the slide gently after it has been air dried. This kills the cells and secures the specimen to the slide.

Heat fixing

Permits ready differentiation of major categories based on the color reaction of cells.

Gram stain

Sphere (round) bacterial shapes.

Coccus

Bacterial shape that has two cocci as a pair together.

Diplococcus

Rod-shaped bacteria

bacillus

Rod-shaped bacteria that are curved at each end.

Vibrio

Rigid and spiral bacteria

Spirilla

Variations in size and shape among the species because they usually lack a cell wall which provides structure.

Pleomorphic

Single flagellum

monotrichous

Flagella at both poles of the cell

amphitrichous

Small bunches, clusters or tufts

lophotrichous

Flagella are dispersed randomly over the entire surface of the cell.

Peritrichous

Microscopic series of tunnels used in transport and storage. Responsible for making proteins and lipids.

End plastic Reticulum

Receives material from the Endoplasmic Reticulum and packages it to be moved to other cells. Produces lysosomes.

Golgi apparatus

Originates in the Golgi apparatus, involved in intracellular digestion and involved in the hydrolysis of food (adding water to breakdown food)

Lysosomes

Membrane bound sacs that store food and water.

Vacuoles

Supply the bulk of the energy of a cell.

Mitochondria

The control center of a cell. Contains DNA, nuclear pores and is separated from the cytoplasm by the nuclear envelope.

Nucleus

Found in fungi, algae and plants. Rigid, provide structural support, and shape.

Cell wall

Long, threadlike filaments with a vegetative body. (Nonreproductive)

Hyphae

One elongated multinucleated giant cell

Coenocytic hyphae

Have cross walls and are divided into individual cell

septate hyphae

Cytoplasmic extensions found in amoeba. Used for movement and food capture.

pseudopodia

Removal of MOST microbes from an animate or inanimate surface. Microbes are reduced in a number from a cleaning technique.

Ex: Washing dishes.

Sanitization

A process that destroys or removes all viable microorganisms, including viruses and endospores. All living cells are destroyed or removed. Done by moist heat under pressure.

Sterilization

Chemical agents used to control microbes on living tissues. Done to prevent infection; usually regulated by the FDA.

Antisepsis

Destroys MOST microbial life by substantially reducing the total population, reducing contamination to inanimate objects. (Non living)

Disinfection