BIO250L EXAM STUDY GUIDE QUESTIONS
AND SOLUTIONS 100 PERCENT CORRECT
VERIFIED ANSWERS
●● what is the objective of a three way streak
Answer: to get one pure colony (strain) of bacteria.
●● what is a pure colony and why do we want to work with pure
cultures
Answer: a pure culture is also called a strain. it dilutes the amount of
bacteria we are working with and makes the final product easier to
observe and work with
●● to grow up a bacterium, it is placed in a medium. the two
requirements that all bacteria need in order to grow is a ___ source, like
tryptone and a ___ source like glucose
Answer: carbon, energy
●● inoculated TSB containing b.cereus goes where
Answer: culture tube waste
●● paper towels after you lysol bench go where
Answer: regular waste
,●● a broken test tube that has been inoculated with m.luteus goes where
Answer: broken glass container
●● name two cultural characteristics that can be used as a basis for
separating microorganisms into taxonomic groups
Answer: form and margin
●● mannitol salt agar is an example of a
Answer: selective and differential medium
●● what is a nosocomial infection and how can you reduce the
occurrence
Answer: is when the patient showed no sign of the infection or bacteria
before entering the hospital facility. the best way to reduce the chance is
through proper hand washing techniques.
●● example of form
Answer: circular
round circle shape of entire structure
●● example of margin
Answer: serrate
, sharp, knife like edge of structure
●● example of elevation
Answer: convex
half moon like raised structure off regular linear line
●● what are virulence factors. describe a mechanism in which virulence
factors aid in pathogenicity
Answer: virulence factors have commensualistic and mutualistic
properties. they aid in antibiotic resistance and allow pathogens to get to
host.
●● describe mannitol salt agar selective and differential functions.
Answer: MSA is selective because it inhibits due to high salt content and
is differential as a mannitol fermenter
●● what is the objective for a streak for isolation of a mixed culture
experiment
Answer: identify and isolate pure colonies of each organism from the
mixed culture which can be viewed, studied, and observed under the
microscope
●● heat fixation is
AND SOLUTIONS 100 PERCENT CORRECT
VERIFIED ANSWERS
●● what is the objective of a three way streak
Answer: to get one pure colony (strain) of bacteria.
●● what is a pure colony and why do we want to work with pure
cultures
Answer: a pure culture is also called a strain. it dilutes the amount of
bacteria we are working with and makes the final product easier to
observe and work with
●● to grow up a bacterium, it is placed in a medium. the two
requirements that all bacteria need in order to grow is a ___ source, like
tryptone and a ___ source like glucose
Answer: carbon, energy
●● inoculated TSB containing b.cereus goes where
Answer: culture tube waste
●● paper towels after you lysol bench go where
Answer: regular waste
,●● a broken test tube that has been inoculated with m.luteus goes where
Answer: broken glass container
●● name two cultural characteristics that can be used as a basis for
separating microorganisms into taxonomic groups
Answer: form and margin
●● mannitol salt agar is an example of a
Answer: selective and differential medium
●● what is a nosocomial infection and how can you reduce the
occurrence
Answer: is when the patient showed no sign of the infection or bacteria
before entering the hospital facility. the best way to reduce the chance is
through proper hand washing techniques.
●● example of form
Answer: circular
round circle shape of entire structure
●● example of margin
Answer: serrate
, sharp, knife like edge of structure
●● example of elevation
Answer: convex
half moon like raised structure off regular linear line
●● what are virulence factors. describe a mechanism in which virulence
factors aid in pathogenicity
Answer: virulence factors have commensualistic and mutualistic
properties. they aid in antibiotic resistance and allow pathogens to get to
host.
●● describe mannitol salt agar selective and differential functions.
Answer: MSA is selective because it inhibits due to high salt content and
is differential as a mannitol fermenter
●● what is the objective for a streak for isolation of a mixed culture
experiment
Answer: identify and isolate pure colonies of each organism from the
mixed culture which can be viewed, studied, and observed under the
microscope
●● heat fixation is
