Question 1

Which scientist is credited with disproving the theory of spontaneous generation through his swan-neck flask experiment?

Accepted Answer

Louis Pasteur

Question 2

Which of the following is a unique characteristic of acid-fast bacteria compared to gram-positive and gram-negative bacteria?

Accepted Answer

High mycolic acid content in the cell wall

Question 3

A bacterial cell is placed in a hypertonic solution. What is the most likely outcome for the cell?

Accepted Answer

The cell will lose water and undergo plasmolysis.

Question 4

Which of the following best describes the function of bacterial flagella?

Accepted Answer

Motility through rotation

Question 5

Which type of microscopy would be most appropriate for viewing the internal structures of a virus at high resolution?

Accepted Answer

Transmission electron microscopy

Question 6

During the Gram stain procedure, what color will a gram-negative cell appear after the application of the decolorizer (alcohol/acetone)?

Accepted Answer

Colorless

Question 7

Which enzyme is responsible for detoxifying hydrogen peroxide in bacterial cells?

Accepted Answer

Catalase

Question 8

A bacterium is found to lack a cell wall. Which genus does it most likely belong to?

Accepted Answer

Mycoplasma

Question 9

Which of the following statements about selective media is correct?

Accepted Answer

It contains substances that inhibit the growth of certain microbes while allowing others to grow.

Question 10

Which of the following best describes the role of NAD and FAD in cellular metabolism?

Accepted Answer

They are electron carriers that shuttle electrons to the electron transport chain.

Question 11

A bacterial culture has a starting population of $$1 	imes 10^3$ cells. If the generation time is 30 minutes, how many cells will there be after 3 hours? Use the formula N_t$$ = $$N_0$$ 	imes 2^n$$, where n$ is the number of generations.

Accepted Answer

$$6.4 	imes 10^4$

Question 12

Which of the following best describes the main difference between substrate-level phosphorylation and oxidative phosphorylation in ATP production?

Accepted Answer

Substrate-level phosphorylation directly transfers a phosphate group to ADP, while oxidative phosphorylation uses a proton gradient and ATP synthase.

Question 13

A culture medium contains beef extract, peptone, and agar. Which type of medium is this?

Accepted Answer

Complex medium

Question 14

Which of the following organisms is classified as a photoautotroph?

Accepted Answer

A cyanobacterium that uses light for energy and $$CO_2 as a $$carbon source

Question 15

How many ATP equivalents are produced from the complete aerobic oxidation of one molecule of glucose in prokaryotes?

Accepted Answer

38

Question 16

Which of the following best describes a psychrophile?

Accepted Answer

An organism that grows best at low temperatures, typically below $$15^\circ C$$

Question 17

Which of the following statements about the electron transport chain (ETC) in bacteria is correct?

Accepted Answer

The ETC generates a proton gradient used to synthesize ATP via ATP synthase.

Question 18

A tube of fluid thioglycollate medium shows bacterial growth only at the very top of the tube. What is the oxygen requirement of this bacterium?

Accepted Answer

Obligate aerobe

Question 19

If a solution contains $$0.01$$ grams of solute in $$100 mL$$, what is the concentration in mg/mL?

Accepted Answer

$$0.1 mg/mL$$

Question 20

Which of the following statements about beta oxidation is correct?

Accepted Answer

Beta oxidation breaks down fatty acids into two-carbon units, producing NADH and FADH$$_2.$$

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