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 the difference between prokaryotic and eukaryotic cells?

Accepted Answer

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

Question 3

A microbiologist is using the streak plate method to isolate bacteria from a mixed sample. What is the primary purpose of this technique?

Accepted Answer

To obtain pure colonies from a mixed culture

Question 4

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 5

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

Accepted Answer

Motility

Question 6

A Gram stain is performed on a bacterial sample. The cells appear purple under the microscope. What does this indicate about the cell wall structure?

Accepted Answer

The bacteria have a thick peptidoglycan layer and no outer membrane.

Question 7

Which of the following is a correct description of the endosymbiotic theory?

Accepted Answer

Eukaryotic cells evolved from prokaryotic cells by engulfing aerobic bacteria, which became mitochondria.

Question 8

Which of the following equations correctly represents the calculation of pH from hydrogen ion concentration?

Accepted Answer

$pH = -\log_{10}[H^+]$

Question 9

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

Accepted Answer

2

Question 10

Which of the following is a product of fermentation that is commonly used to identify bacteria?

Accepted Answer

Lactic acid

Question 11

A bacterial cell is placed in a hypertonic solution. What will most likely happen to the cell?

Accepted Answer

The cell will lose water and shrink (plasmolysis).

Question 12

Which of the following best describes competitive inhibition in enzyme activity?

Accepted Answer

An inhibitor binds to the active site, preventing substrate binding.

Question 13

Which of the following is NOT a function of the cytoplasmic membrane in bacteria?

Accepted Answer

Protein synthesis

Question 14

Which of the following best explains why obligate anaerobes cannot survive in the presence of oxygen?

Accepted Answer

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

Question 15

Which of the following is a correct description of binary fission in bacteria?

Accepted Answer

A process where a single cell divides into two identical daughter cells.

Question 16

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

Accepted Answer

Plate count method

Question 17

Which of the following is a major contribution of Robert Koch to microbiology?

Accepted Answer

Establishment of the method for isolating pure cultures

Question 18

Which of the following best describes the structure of a phospholipid bilayer in the cytoplasmic membrane?

Accepted Answer

Hydrophilic heads face outward, hydrophobic tails face inward.

Question 19

Which of the following is a distinguishing feature of Gram-negative bacteria compared to Gram-positive bacteria?

Accepted Answer

Presence of an outer membrane containing lipopolysaccharide

Question 20

Which of the following is the correct sequence of events in the lytic cycle of a bacteriophage?

Accepted Answer

Attachment, penetration, biosynthesis, maturation, release

Microbiology Exam 1 Study Guide: Chapters 1–6

Study Guide - Practice Questions

Study Guide - Flashcards