Question 1

Which scientist is credited with disproving the theory of spontaneous generation by demonstrating that microorganisms do not arise from nonliving matter?

Accepted Answer

Louis Pasteur

Question 2

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

Accepted Answer

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

Question 3

Which of the following is NOT one of Koch's postulates?

Accepted Answer

The microorganism must be able to survive outside the host for at least 24 hours.

Question 4

A scientist is studying the pH scale and measures a solution with a pH of 4. How many times more acidic is this solution compared to a solution with a pH of 7?

Accepted Answer

$10^3$

Question 5

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

Accepted Answer

It provides motility by rotating like a propeller.

Question 6

Gram-positive and Gram-negative bacteria differ in their cell wall structure. Which feature is unique to Gram-negative bacteria?

Accepted Answer

An outer membrane containing lipopolysaccharide (LPS)

Question 7

Which process is described by the equation $C_6H_{12}O_6 + 6O_2 ightarrow 6CO_2 + 6H_2O + 	ext{energy}$?

Accepted Answer

Aerobic respiration

Question 8

During glycolysis, how many net ATP molecules are produced per molecule of glucose?

Accepted Answer

$2$

Question 9

Which of the following is a competitive inhibitor of the enzyme succinate dehydrogenase in the Krebs cycle?

Accepted Answer

Malonate

Question 10

A bacterial culture is grown in a medium containing only glucose and no oxygen. Which metabolic pathway will the bacteria most likely use to generate energy?

Accepted Answer

Fermentation

Question 11

Which of the following statements about the phospholipid bilayer of the cytoplasmic membrane is correct?

Accepted Answer

It creates a selectively permeable barrier due to hydrophobic and hydrophilic regions.

Question 12

Which of the following is a direct method for measuring bacterial reproduction that requires incubation?

Accepted Answer

Plate count method

Question 13

Which of the following best explains why obligate anaerobes are killed by oxygen?

Accepted Answer

They lack enzymes such as superoxide dismutase and catalase to detoxify reactive oxygen species.

Question 14

Which of the following is NOT a function of the bacterial cytoplasm?

Accepted Answer

Site of photosynthesis

Question 15

Which of the following best describes the streak plate method?

Accepted Answer

It is used to isolate pure colonies from a mixed culture.

Question 16

Which of the following is a product of fermentation that is useful in identifying bacteria?

Accepted Answer

Lactic acid

Question 17

Which of the following is a major function of ribosomes in both prokaryotic and eukaryotic cells?

Accepted Answer

Protein synthesis

Question 18

Which of the following best describes the endosymbiotic theory?

Accepted Answer

Eukaryotic cells evolved from prokaryotic cells by engulfing aerobic and photosynthetic bacteria.

Question 19

Which of the following is a nitrogen-fixing microorganism?

Accepted Answer

Rhizobium

Question 20

Which of the following is the correct order of the phases in a typical bacterial growth curve?

Accepted Answer

Lag phase, log phase, stationary phase, death phase

Microbiology Exam 1 Study Guide: Chapters 1–6

Study Guide - Practice Questions

Study Guide - Flashcards