EXAM PAPER 2026 QUESTIONS WITH
ANSWERS GRADED A+
◉ A bacterial isolate is subcultured to two blood agar plates, one of
which is incubated in an anaerobe jar, and the other is incubated on a
shelf in the incubator. After incubation, growth is observed on the plate
from the anaerobe jar, but there is not growth on the plate incubated on
the incubator shelf. Based on these results how would this organism be
categorized.. Answer: obligate anaerobe
◉ Where would you predict an facultative anaerobe would grow in a
tube of fluid thioglycolate medium.. Answer: throughout the tube
◉ The pink color in the top of the broth in an FTM tube indicates..
Answer: the presence of oxygen
◉ Both human pathogens and normal microbiota are typically classified
as.. Answer: mesophiles
◉ Taq polymersae is a DNA polymerase enzyme that demonstrates
maximal activity at 72C. The organism from which this enzyme was
isolated would most likely be classified as a.. Answer: thermophile
, ◉ Vibrio cholerae is the bacterium responsible for cholera, a GI tract
infection. Normally, it takes the ingestion of over one million bacterial
cells to cause infection, but the consumption of antacids significantly
lowers this number. What does this tell you about the likely
classification of V. cholerae in terms of pH preference.. Answer: it is
likely an alkaliphile
◉ How does pH negatively affect the metabolism of microorganisms..
Answer: pH changes can denature enzymes
◉ Why can jams and honey be stored at room temperature for long
periods of time.. Answer: the high sugar content causes plasmolysis of
bacterial cells
◉ Microorganisms that can grow at salt concentrations as high as 15-
30% are known as.. Answer: halophiles
◉ An experiment involves the inoculation bacteria onto a variety of
media with NaCl concentrations ranging from 1% to 25%. Which of
these media is most likely to be isotonic with the bacterial cells..
Answer: 1%
◉ Which of the following would be appropriately sterilized using UV
radiation.. Answer: stainless steel surface in biological safety cabinet
used for media preparation