micro quiz (physiology-synergism)

bacterial reproduction

asexual process whereby one cell increases in size and forms two cells; identical to each other. simple transverse division

binary fission

a method of asexual reproduction involving halving of the nucleus and cytoplasm of the cell following by the development of each half into a new cell-replicating itself

bacterial colony

a visible mass of microorganisms, usually of a single type

pure colonies

single type

mixed colonies

colonies growing together and touching each other containing more than one kind of bactera

culture

medium for which bacteria are grown. agar-plate

autotrophic bacteria

self-feeding organisms. require only simple inorganic substances like carbon, nitrogen, hydrogen, oxygen. self sufficient, do not need organic compounds for growth. free living and do not cause disease

heterotrophic bacteria

microorganisms (yeast, mold, bacteria) that use organic carbon as food. rely on other organisms- both plants and animals for nutrition. major cause of disease

strict saprophytes

a plant, fungus, or microorganism that lives on dead or decaying organic matter. grows on dead tissue. requires non-living organic matter

strict obligate parasites

require living organic matter. parasites need a living host

facultative parasites

prefer dead organic matter for growth

facultative saprophyte

prefers living organic matter.

strict anaerobes

require the ABSENCE of oxygen as found in the air

strict aerobes

need oxygen as found in the air

microaerobic

needs only a little oxygen

facultative aerobe

prefers the absence of oxygen

facultative anaerobe

prefers the presence of oxygen

how facultative bacteria get food

use either dissolved oxygen or get it from food materials like sulfate or nitrate

capnophilic bacteria

microorganisms that thrive in the presence of high concentrations of carbon dioxide

hydrogen ion concentration

measures the acidity-alkalinity content of an organism

some bacteria can tolerate acidic conditions as low as

6.5

some bacteria can tolerate alkaline conditions as high as

7.5

thermophiles

heat loving bacteria that prefer temps above 45c. found in naturally occurring hot springs. no human disease

mesophiles

prefer the mid-range temps. most human pathogens are found in this group.

psychrophiles

akk cryophiles. prefer cold temps

all light is_____to bacteria

detrimental

to bacteria, light is

bacteriostatic

how does ultraviolet kill bacteria?

through mutation. causes dna mutations

osmotic pressure

the presence of solutes such as salt or sugar in a solvent such as water that induce changes in the size, volume, and viability of bacterial cells

osmosis

passage of a solvent through a semi permeable mebrane from a divide to a higher concentration. so as to equal concentrations on both sides

hypertonic solution

greater concentration of salt outside the cell than inside. movement of solvent out of the cell. cells shrink-plasmolysis

isotonic solution

equal concentration of solute out and inside the cell

hypotonic solution

lesser concentration of salt outside the cell. movement of solvent into the cell. cell swells and burst-plasmoptysis

symbiosis

two populations of organisms interact in a close and permanent association

benefits of symbiosis

food, protection, support. ultimate interdependence of two organisms. each organism absolutely requires the other for life