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 determine if a specific microorganism causes a specific disease.

Question 2

Which of the following statements about prokaryotic and eukaryotic cells is correct?

Accepted Answer

Prokaryotic cells lack a membrane-bound nucleus, while eukaryotic cells have a membrane-bound nucleus.

Question 3

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 4

Which of the following best explains the difference between dehydration synthesis and hydrolysis reactions?

Accepted Answer

Dehydration synthesis joins monomers by removing water, while hydrolysis breaks polymers by adding water.

Question 5

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

Accepted Answer

It assists in the transfer of genetic material during conjugation.

Question 6

A scientist isolates a microorganism that is unicellular, lacks a nucleus, and has peptidoglycan in its cell wall. To which domain does this organism most likely belong?

Accepted Answer

Bacteria

Question 7

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

Accepted Answer

ATP stores and transfers energy for cellular processes.

Question 8

Which of the following statements about endospores is correct?

Accepted Answer

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

Question 9

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

Accepted Answer

Viruses cannot carry out metabolism or reproduce independently.

Question 10

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

Accepted Answer

They have an outer membrane containing lipopolysaccharides.

Question 11

Which of the following best describes the difference between an obligate pathogen and an opportunistic pathogen?

Accepted Answer

Obligate pathogens always cause disease in a host, while opportunistic pathogens cause disease only under certain conditions.

Question 12

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

Accepted Answer

Hydrogen bonds are present in the secondary structure of proteins.

Question 13

Which of the following best describes the process of conjugation in bacteria?

Accepted Answer

It is the transfer of genetic material from one bacterium to another via a pilus.

Question 14

Which of the following is a correct statement about the difference between archaea and bacteria?

Accepted Answer

Archaea have unique membrane lipids not found in bacteria.

Question 15

A solution of pH 2 is mixed with a solution of pH 5 in equal volumes. What is the resulting pH of the mixture, assuming volumes are additive and no other reactions occur?

Accepted Answer

$[H^+]_{	ext{mix}} = \frac{[H^+]_{pH2} + [H^+]_{pH5}}{2}$, so $[H^+]_{	ext{mix}} = \frac{1 	imes 10^{-2} + 1 	imes 10^{-5}}{2} \approx 5.005 	imes 10^{-3}$, so pH $\approx 2.3$

Question 16

Which of the following is a correct statement about the function of ribosomes?

Accepted Answer

Ribosomes are the site of protein synthesis in both prokaryotic and eukaryotic cells.

Question 17

Which of the following best describes the role of the plasma membrane in bacteria?

Accepted Answer

It regulates the movement of substances into and out of the cell.

Question 18

Which of the following is a correct statement about the difference between exergonic and endergonic reactions?

Accepted Answer

Exergonic reactions release energy, while endergonic reactions require an input of energy.

Question 19

Which of the following best explains the endosymbiotic theory for the origin of mitochondria in eukaryotic cells?

Accepted Answer

Mitochondria originated from free-living prokaryotes that were engulfed by ancestral eukaryotic cells.

Question 20

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

Accepted Answer

Prokaryotic DNA is typically a single, circular chromosome located in the nucleoid region.

Microbiology Exam Study Guide: Chapters 1-3

Study Guide - Practice Questions

Study Guide - Flashcards