MCB 2 & 3 quiz

In which phase does the bacteria increase in size but does not multiple?

• log phase

• stationary phase

• lag phase

• death phase

what is the main disadvantage of total cell count method

Answer explanation

total cell count counts both dead and live cells, which make it not as accurate as viable cell count

what is an ingredient nutrient agar has but nutrient broth does not have?

• microelements

• agar

• macronutrients

• peptones

when do we use nutrient broth?

• to cultivate pure cultures in large quantities

• to count colonies

• for serial dilution

• to view colony morphology

what is the structure of the cell wall of gram positive bacteria?

• high amounts of teichoic acid

• has LPS

• 90% peptidoglycan

• 10% peptidoglycan

what is the purpose of adding iodine during gram staining?

Answer explanation

to create a crystal violet iodine complex so it would not be easily washed off the cell wall of the gram positive bacterial

what is another test to determine gram reaction of bacteria?

• API 20E

• 16 streak

• KOH test

• kirby bauer

which antibiotic inhibit cell wall synthesis?

• polymyxins

• pencillin

• rifamycin

• tetracyclines

this bacteria grows best at pH 5.5 and at 37°C. Which bacteria classification does this bacteria belong to?

• thermophile and neutriphile

• hyperthermophile and acidophile

• mesophile and neutrophile

• mesophile and alkaliphile

which group does this bacteria belong to?

• aerotolerant anaerobe

• strict anaerobe

• obligate aerobe

• microaerophile