Portage Microbiology Exam #4 questions
and answers 2025\2026 A+ Grade
True or False: Growth media is best suited for distinguishing between two similar species of bacteria
- correct answer False. Growth media is designed to simply support (and not restrict) microbial growth
A researcher is asked to determine which of two vials contains e coli and which contains salmonella.
Knowing both gram-negative while only one of them is capable of fermenting lactose, which type of
media would be best suited (multiple choice)
- correct answer Differential media distinguishes between two, often related, microbes
What are the requirements of a fastidious microbe? (short answer)
- correct answer A fastidious microbe is an organism with complex growth requirements such that is
absent it will not grow. Enriched medias thus contain these specific and essential nutrients required for
the growth of a particular subset of microorganisms.
True or False: LB agar is classified as a selective, non-differential media
- correct answer False
What is agar used for in microbiology? (short answer)
- correct answer Agar is used to create a solid, smooth surface on which microbes can grow
Alpha hemolysis (matching)
- correct answer Incomplete hemolytic activity
Beta hemolysis (matching)
- correct answer Complete hemolytic activity
and answers 2025\2026 A+ Grade
True or False: Growth media is best suited for distinguishing between two similar species of bacteria
- correct answer False. Growth media is designed to simply support (and not restrict) microbial growth
A researcher is asked to determine which of two vials contains e coli and which contains salmonella.
Knowing both gram-negative while only one of them is capable of fermenting lactose, which type of
media would be best suited (multiple choice)
- correct answer Differential media distinguishes between two, often related, microbes
What are the requirements of a fastidious microbe? (short answer)
- correct answer A fastidious microbe is an organism with complex growth requirements such that is
absent it will not grow. Enriched medias thus contain these specific and essential nutrients required for
the growth of a particular subset of microorganisms.
True or False: LB agar is classified as a selective, non-differential media
- correct answer False
What is agar used for in microbiology? (short answer)
- correct answer Agar is used to create a solid, smooth surface on which microbes can grow
Alpha hemolysis (matching)
- correct answer Incomplete hemolytic activity
Beta hemolysis (matching)
- correct answer Complete hemolytic activity
