1. Which of the following are the peculiarities of Shigella sp.? They are: 1. glucose-positive 2. gram-negative rods 3. facultative anaerobes 4. endospore-forming

The correct answer is 2. gram-negative rods.<br /><br />Shigella sp. are gram-negative rods, which means they do not retain the crystal violet stain used in the Gram staining method and appear pink or red under a microscope. They are also facultative anaerobes can grow in both the presence and absence of oxygen. However, they are not glucose-positive and do not form endospores.