Q: A solution has a pH of 3. What is the concentration of hydrogen ions $[H^+]$ in this solution?

$[H^+] = 1 \times 10^{-3} \ \mathrm{mol/L}$

Question 1

Which of the following best describes Koch's postulates and their significance in microbiology?

Accepted Answer

They are a set of criteria used to establish a causal relationship between a microbe and a specific disease.

Question 2

A scientist isolates a new microorganism and observes that it lacks a nucleus, has a peptidoglycan cell wall, and reproduces by binary fission. To which domain does this organism most likely belong?

Accepted Answer

Bacteria

Question 3

Which of the following statements about endospores is correct?

Accepted Answer

Endospores are highly resistant structures formed by certain bacteria to survive harsh conditions.

Question 4

Which of the following best explains the difference between an opportunistic pathogen and a primary pathogen?

Accepted Answer

An opportunistic pathogen causes disease only in hosts with weakened immune systems, while a primary pathogen can cause disease in healthy individuals.

Question 5

A solution has a pH of 3. What is the concentration of hydrogen ions $[H^+]$ in this solution?

Accepted Answer

$[H^+] = 1 	imes 10^{-3} \ \mathrm{mol/L}$

Question 6

Which of the following best describes dehydration synthesis?

Accepted Answer

It is a chemical reaction in which two molecules are joined together by removing a molecule of water.

Question 7

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

Accepted Answer

It serves as the site of protein synthesis.

Question 8

A patient is diagnosed with a bacterial infection. The bacteria are found to be Gram-negative. Which of the following statements about Gram-negative bacteria is correct?

Accepted Answer

They have a thin peptidoglycan layer and an outer membrane containing lipopolysaccharides.

Question 9

Which of the following best describes the function of ATP in the cell?

Accepted Answer

ATP stores and provides energy for many cellular processes.

Question 10

Which of the following statements about the endosymbiotic theory is correct?

Accepted Answer

It proposes that mitochondria and chloroplasts originated from free-living prokaryotes that were engulfed by ancestral eukaryotic cells.

Question 11

Which of the following is a correct comparison between prokaryotic and eukaryotic flagella?

Accepted Answer

Prokaryotic flagella are composed of flagellin and rotate, while eukaryotic flagella are composed of microtubules and move in a whip-like motion.

Question 12

Which of the following best describes the role of ribosomes in the cell?

Accepted Answer

They are the sites of protein synthesis.

Question 13

A scientist is studying a macromolecule composed of amino acids linked by peptide bonds. Which class of biological macromolecule is this?

Accepted Answer

Protein

Question 14

Which of the following is a correct statement about the structure of DNA?

Accepted Answer

DNA is a double helix composed of two antiparallel strands held together by hydrogen bonds between complementary bases.

Question 15

Which of the following best explains why viruses are not classified as living organisms?

Accepted Answer

They cannot carry out metabolism or reproduce independently outside a host cell.

Question 16

A patient is infected with a protozoan parasite that reproduces by binary fission and forms cysts. Which of the following best describes this organism?

Accepted Answer

It is a unicellular eukaryote that can survive harsh conditions by forming cysts.

Question 17

Which of the following is a correct statement about the Gram stain?

Accepted Answer

It differentiates bacteria based on differences in their cell wall structure.

Question 18

Which of the following best describes the function of lysosomes in eukaryotic cells?

Accepted Answer

They contain hydrolytic enzymes that break down waste materials and cellular debris.

Question 19

A solution of pH 2 is diluted 100-fold with pure water. What is the new pH of the solution?

Accepted Answer

pH 4

Question 20

Which of the following statements about biofilms is correct?

Accepted Answer

Biofilms are communities of microorganisms attached to a surface and embedded in a self-produced extracellular matrix.

Microbiology Exam Study Guide: Chapters 1-3

Study Guide - Practice Questions

Study Guide - Flashcards