Question 1

Which of the following statements best explains why Archaea are classified separately from Bacteria in the three-domain system?

Accepted Answer

Archaea possess unique ribosomal RNA sequences and lack peptidoglycan in their cell walls.

Question 2

A patient is diagnosed with a bacterial infection caused by a Gram-negative organism. Which structural feature is most responsible for the organism's resistance to certain antibiotics and its ability to cause fever?

Accepted Answer

Lipopolysaccharide (LPS) in the outer membrane, specifically Lipid A

Question 3

Which of the following best describes the process of substrate-level phosphorylation?

Accepted Answer

ATP is generated by the direct transfer of a phosphate group from a phosphorylated substrate to ADP.

Question 4

A microbiologist isolates a microorganism that grows optimally at 55°C, can survive in 10% NaCl, and does not have peptidoglycan in its cell wall. Which group does this organism most likely belong to?

Accepted Answer

Archaea

Question 5

Which of the following equations correctly calculates the final number of bacteria ($$M_f) $$after $$n$$ generations, starting from an initial number ($$M_i$$)?

Accepted Answer

$$M_f = M_i 	imes 2^n$$

Question 6

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

Accepted Answer

Energy production via ATP synthesis

Question 7

A scientist is studying a microbe that can use light as an energy source and CO$$_2 as a $$carbon source. What is the correct nutritional classification for this organism?

Accepted Answer

Photoautotroph

Question 8

Which of the following best explains why viruses are not classified within the three-domain system?

Accepted Answer

Viruses lack a plasma membrane and do not consist of cells.

Question 9

During glycolysis, what is the net gain of ATP molecules per molecule of glucose metabolized?

Accepted Answer

2 ATP

Question 10

Which of the following statements about endospores is TRUE?

Accepted Answer

Endospores are metabolically inactive and highly resistant to environmental stress.

Question 11

A bacterial culture is transferred from a nutrient-rich medium to a fresh medium. Which phase of the bacterial growth curve is characterized by intense metabolic activity but little or no cell division?

Accepted Answer

Lag phase

Question 12

Which of the following best describes the function of superoxide dismutase (SOD) in aerobic bacteria?

Accepted Answer

It converts superoxide radicals ($$O_2$$^-$$) into hydrogen peroxide (H_2O_2$) and oxygen (O_2$).

Question 13

Which of the following is a correct pairing of a macromolecule with its monomer?

Accepted Answer

Nucleic acid – Nucleotide

Question 14

A bacterial cell is placed in a hypertonic solution. What is the most likely outcome for the cell?

Accepted Answer

The cell will undergo plasmolysis as water leaves the cell.

Question 15

Which of the following statements about the electron transport chain (ETC) in prokaryotes is correct?

Accepted Answer

The ETC generates a proton gradient across the plasma membrane, which drives ATP synthesis.

Question 16

Which of the following best describes the role of teichoic acids in Gram-positive bacteria?

Accepted Answer

They provide structural stability and are covalently attached to peptidoglycan.

Question 17

A scientist is studying a bacterium that can grow in the presence or absence of oxygen, but grows better when oxygen is present. What is the correct term for this organism?

Accepted Answer

Facultative anaerobe

Question 18

Which of the following is a unique feature of eukaryotic flagella compared to prokaryotic flagella?

Accepted Answer

Eukaryotic flagella have a 9+2 arrangement of microtubules and move in a wave-like manner.

Question 19

Which of the following best explains why Mycoplasma species are resistant to penicillin?

Accepted Answer

They lack a cell wall and therefore do not have peptidoglycan.

Question 20

Which of the following best describes the process of denaturation in proteins?

Accepted Answer

It is the loss of secondary, tertiary, and quaternary structure due to heat, acid, or chemicals, resulting in loss of function.

Microbiology Foundations: Mini-Textbook Study Notes (Chapters 1–6)

Guida di studio - Domande di pratica

Study guide - Flashcard