This procedure or technique minimizes the chance of other organisms being accidentally introduced
Aseptic Technique
100
A growth curve is characterized by what five distinct stages?
Lag Phase, Exponential or log, stationary, death, and a phase of prolonged decline
100
What is a two part covered container made of glass or plastic in which solid culture medium is contained in?
Petri Dish
200
A population descended from a single cell is a _____?
Pure Culture
200
What factors does the generation time typically depend on for bacterial growth?
The Species and Growth conditions
200
About how many cells are required for a colony to be easily visible to the naked eye?
1 million cells
200
What is the optimum pH for growth of most species of bacteria?
pH 7
200
The scientist that contributed most to the development of pure culture techniques was ______?
Robert Koch
300
A culture medium that contains protein digests, extracts, or other ingredients that vary in their chemical composition
Complex Medium
300
What is the cause for slipperiness of rocks in a stream bed, the slimy coat that covers kitchens drains, and the dental plaque that typically forms on teeth
Biofilms
300
What are some reasons as to why agar is used in contrast to gelatin and other gelling agents?
Agar is not destroyed at high temperatures and can be sterilized by heating. Agar remains solid over the entire temperature range at which most microbes grow.
300
What are the small molecules made by cells as they multiply called?
Primary metabolites
300
What is the name of a culture that is stored for use as an inoculum in later procedures?
Stock Culture
400
Stage in the growth curve during which cells divide at a constant rate
Exponential (Log) Phase
400
Differential media only allows certain bacteria to grow?
(T or F)
FALSE
400
A single bacterial cell may multiply to form a visible colony
(T or F)
True
400
This method is used to determine an organisms oxygen requirement
Shake Tube Method
400
This is a type of system in which nutrients and wastes are not removed
Closed Systems or Batch Cultures
500
A polysaccharide extracted from marine algae. It is used to solidify culture media
Agar
500
Why do microbes become hundreds of times more resistant to disinfectants than their planktonic counterparts?
The reason is due to the biofilm structure which shields the microbes within from the effects of disinfectants.
500
What is the simplest and most commonly used technique for isolating prokaryotes?
Streak-Plate method
500
A hot tub (approx 104 deg F or 40 deg C) would most likely contain what type of species ____?
Mesophiles
500
This type of system is required to maintain continuous growth. Nutrients are added and wastes are removed continuously