A microbiology student is examining a sample suspected of co…

A microbiology student is examining a sample suspected of containing Mycobacterium tuberculosis. They note that the bacteria do not readily take up Gram stain dyes and appear acid-fast when stained using the Ziehl-Neelsen method. Question:Which structural feature of M. tuberculosis explains why it is acid-fast and resistant to conventional Gram staining?

BONUS QUESTION. Researchers have recently discovered unusual…

BONUS QUESTION. Researchers have recently discovered unusual circular RNAs in the human gut microbiota, termed Obelisks. These RNAs are small (~300 nucleotides), circular, single-stranded, and non-coding. They show ribozyme activity and are only detected in gut bacteria that are co-infected with specific bacteriophages. Interestingly, Obelisks are sometimes found inside viral particles but can also exist freely in the cytoplasm. Based on the characteristics described, which acellular pathogen type do Obelisks most closely resemble? [color1] Which of the following would be the most appropriate experimental strategy to detect and study Obelisks in the human gut? [color2] How might Obelisks influence the human gut microbiota if they replicate within bacteria co-infected by bacteriophages? [color3]

During a microbiology lab, a student performs a Gram stain o…

During a microbiology lab, a student performs a Gram stain on an unknown bacterial sample but accidentally omits the safranin step. After observing the slide under the microscope, the student notices that some cells are visible while others are not. Question:What would be the expected result of leaving out the safranin in the Gram stain procedure?