Question 1

Which of the following best describes the difference between prokaryotic and eukaryotic cells?

Accepted Answer

Eukaryotic cells have a nucleus, while prokaryotic cells lack a nucleus.

Question 2

A bacterial cell measures $$10\ \mu m in $$length. How many nanometers is this?

Accepted Answer

$$10\ \mu m = 10,000\ nm$$

Question 3

Which of the following statements about Gram staining is correct?

Accepted Answer

Gram-positive cells retain the crystal violet stain and appear purple after the alcohol wash.

Question 4

Which scientist is credited with disproving spontaneous generation using a swan-neck flask experiment?

Accepted Answer

Louis Pasteur

Question 5

A microbe is classified as a strict anaerobe. Which of the following best describes its oxygen requirements?

Accepted Answer

It cannot tolerate oxygen and will die in its presence.

Question 6

Which of the following is a beneficial activity of microorganisms?

Accepted Answer

Producing antibiotics

Question 7

Which of the following best explains why mycoplasmas are resistant to antibiotics that interfere with cell wall synthesis?

Accepted Answer

They lack a cell wall.

Question 8

Which of the following is the correct scientific nomenclature for the bacterium that causes tuberculosis?

Accepted Answer

Mycobacterium tuberculosis

Question 9

A culture medium contains radioactive sulfur ($$^{35}S). In $$which cellular molecules would you expect to find the $$^{35}S$$?

Accepted Answer

Proteins

Question 10

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

Accepted Answer

They protect bacteria from phagocytosis.

Question 11

Which of the following is NOT a method of microbial control that relies on physical means?

Accepted Answer

Alcohol disinfection

Question 12

Which of the following statements about biofilms is correct?

Accepted Answer

Biofilms provide increased resistance to antibiotics.

Question 13

Which of the following best describes the process of binary fission in bacteria?

Accepted Answer

Bacteria divide by binary fission, producing two identical daughter cells.

Question 14

A microscope has a resolution of $$0.2\ nm. $$What does this mean?

Accepted Answer

It can distinguish two points that are at least $$0.2\ nm$$ apart.

Question 15

Which of the following is a direct method for measuring microbial growth?

Accepted Answer

Plate count

Question 16

Which of the following statements about Koch’s postulates is correct?

Accepted Answer

They provide a framework for linking a specific microbe to a specific disease.

Question 17

Which of the following is a reason why gram-negative bacteria are more resistant to chemical biocides than gram-positive bacteria?

Accepted Answer

Gram-negative bacteria possess an outer membrane that restricts entry of biocides.

Question 18

Which of the following is an example of biotechnology that uses recombinant DNA technology?

Accepted Answer

Production of human insulin by genetically modified bacteria

Question 19

Which of the following is the most obvious way for a microbe to avoid damage from toxic forms of oxygen?

Accepted Answer

Produce catalase and superoxide dismutase enzymes

Question 20

A bacterial population doubles every 30 minutes. If you start with 1,000 cells, how many cells will there be after 2 hours?

Accepted Answer

$$1,000 	imes 2^4$ = 16,000$$

Microbiology Exam 1 Study Guide: Chapters 1, 3, 4, 6, 7

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