Question 1

Which of the following features is present in eukaryotic cells but absent in prokaryotic cells?

Accepted Answer

Membrane-bound organelles

Question 2

A microbiologist isolates a bacterium with a thick peptidoglycan layer, teichoic acids, and no outer membrane. What color would this bacterium appear after Gram staining, and why?

Accepted Answer

Purple, because it is Gram-positive and retains crystal violet

Question 3

Which structure allows Neisseria gonorrhoeae to adhere to human mucosal surfaces, contributing to its pathogenicity?

Accepted Answer

Fimbriae

Question 4

A patient is diagnosed with pneumonia caused by Streptococcus pneumoniae. The strain isolated lacks a capsule. What is the most likely consequence of this absence?

Accepted Answer

The bacterium will be non-pathogenic

Question 5

Which of the following best explains why penicillin is more effective against Gram-positive bacteria than Gram-negative bacteria?

Accepted Answer

Gram-positive bacteria have a thick peptidoglycan layer that is the target of penicillin

Question 6

Which of the following arrangements describes a cluster of spherical bacterial cells?

Accepted Answer

Staphylococci

Question 7

A bacterium is identified as a spirochete. Which of the following diseases could it potentially cause?

Accepted Answer

Lyme disease

Question 8

Which of the following statements about bacterial plasmids is correct?

Accepted Answer

They are small, circular DNA molecules that can carry antibiotic resistance genes

Question 9

A patient presents with a severe infection caused by a Gram-negative bacterium. Which component of the bacterial cell wall is most likely responsible for the patient's fever and shock symptoms?

Accepted Answer

Lipid A of lipopolysaccharide (LPS)

Question 10

Which antibiotic targets the bacterial ribosome, thereby inhibiting protein synthesis?

Accepted Answer

Erythromycin

Question 11

Why are endospores a significant concern in food safety and sterilization procedures?

Accepted Answer

They can survive harsh conditions and persist after standard boiling

Question 12

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

Accepted Answer

It aids in adherence to surfaces and can protect against phagocytosis

Question 13

A laboratory technician is working with a bacterium that is susceptible to lysozyme and stains purple with Gram stain. Which of the following is most likely true about this bacterium?

Accepted Answer

It contains teichoic acids in its cell wall

Question 14

Which of the following is a correct pairing of bacterial shape and example?

Accepted Answer

Coccus – spherical

Question 15

A patient is prescribed polymyxin for a Gram-negative bacterial infection. Why must the dosage be carefully monitored?

Accepted Answer

Polymyxin has a narrow therapeutic index, meaning the toxic dose is close to the therapeutic dose

Question 16

Which of the following best explains why Mycoplasma pneumoniae is resistant to antibiotics that target cell wall synthesis?

Accepted Answer

It lacks a cell wall

Question 17

Which of the following is a function of pili in bacteria?

Accepted Answer

Transfer of DNA between cells (conjugation)

Question 18

A Gram-negative bacterium is identified by the presence of an O polysaccharide. What is the significance of this structure?

Accepted Answer

It is used to differentiate serovars of the species

Question 19

Which of the following best describes the arrangement of bacilli in a 'strepto-' configuration?

Accepted Answer

A chain of rod-shaped cells

Question 20

A patient is infected with a bacterium that is identified as acid-fast positive. Which disease is most likely associated with this bacterium?

Accepted Answer

Tuberculosis

Functional Anatomy of Prokaryotic and Eukaryotic Cells: An Overview

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