Question 1

Which experiment helped disprove the theory of spontaneous generation, and what was its key finding?

Accepted Answer

Pasteur's swan-neck flask experiment, which showed that microorganisms do not arise from nonliving matter but from contamination.

Question 2

Which of the following is NOT a difference between prokaryotic and eukaryotic cells?

Accepted Answer

Prokaryotic cells have a nucleus, while eukaryotic cells do not.

Question 3

A bacterial cell is described as 'gram positive.' What does this mean about its cell wall structure?

Accepted Answer

It has a thick layer of peptidoglycan and retains the crystal violet stain.

Question 4

Which bacterial shape is described as spherical and often forms chains or clusters?

Accepted Answer

Coccus

Question 5

During which phase of the bacterial growth curve do cells prepare for division but do not increase in number?

Accepted Answer

Lag phase

Question 6

What is the primary function of bacterial endospores?

Accepted Answer

To allow bacteria to survive harsh environmental conditions.

Question 7

Which of the following best describes an obligate anaerobe?

Accepted Answer

An organism that cannot survive in the presence of oxygen.

Question 8

Enzymes speed up chemical reactions by:

Accepted Answer

Lowering the activation energy ($$E_A) $$required for the reaction.

Question 9

Which statement about enzymes is TRUE?

Accepted Answer

Enzymes are not consumed during the reaction and can be reused.

Question 10

A repressible operon is typically turned off when:

Accepted Answer

The end product of the pathway is abundant and binds to the repressor.

Question 11

Which of the following is an example of horizontal gene transfer in bacteria?

Accepted Answer

Conjugation, where DNA is transferred between cells via a pilus.

Question 12

A mutation in a bacterial gene leads to antibiotic resistance. What type of mutation is this considered?

Accepted Answer

Beneficial mutation

Question 13

Which of the following best describes a plasmid?

Accepted Answer

A small, circular piece of DNA independent of the bacterial chromosome.

Question 14

Which step is FIRST in the viral infection cycle?

Accepted Answer

Attachment of the virus to the host cell.

Question 15

Why are booster vaccines sometimes necessary?

Accepted Answer

Because viruses can mutate, changing their antigens and reducing immunity over time.

Question 16

Which of the following is a real-world example of a persistent viral infection?

Accepted Answer

Herpes simplex virus, which can remain dormant and reactivate later.

Question 17

Which of the following mechanisms allows a bacteriophage to integrate its DNA into the host genome?

Accepted Answer

Lysogenic cycle

Question 18

A thermophile is an organism that thrives in which type of environment?

Accepted Answer

High temperature environments, such as hot springs.

Question 19

Which formula correctly represents the exponential growth of a bacterial population?

Accepted Answer

$$N = N_0$ 	imes 2^n$$

Question 20

Which of the following is a key reason why treating viral infections is more challenging than treating bacterial infections?

Accepted Answer

Viruses use host cell machinery for replication, making it difficult to target them without harming host cells.

Microbiology Foundations for Anatomy & Physiology: Cells, Bacteria, Viruses, and Genetic Mechanisms

Study Guide - Practice Questions