Ex. 12 Pour Plate Techniques

Question 1

mixed culture

Answer 1

environments that contain many diff organisms together in communities

Question 2

pure culture

Answer 2

all organisms descended from one bacterial cells

Question 3

two dilution techniques used to separate individual bacteria

Answer 3

pour plates and streak plates

Question 4

loop dilution series

Answer 4

pour plates using serial dilution (each tube diluted from previous tube)

Question 5

how can we estimate quantity of bacteria

Answer 5

serial dilution carried out by transferring known volume of broth to each tube

Question 6

extinction point

Answer 6

species present in low numbers are diluted beyond the point where it no longer exists before appearing on a plate

Question 7

why are some plates TFTC

Answer 7

appearance of fewer than 30 clones may be a chance event

Question 8

why are some plates TMTC

Answer 8

too much crowded for accurate count

Question 9

Quebec colony counter

Answer 9

holds petri dish and provides a magnifying glass to look through

Question 10

why is agar used as media

Answer 10

few microbes degrade agar, so it will remain solid during microbial growth. liquifies at 100C, remains in liquid state until cools off below 40C. once solidified can be incubated up to 100C and remain solid