1. Multiple Choice: Which of the following is an essential feature of the Gram staining technique? A) Alcohol-acetone decolorization B) Counterstaining with safranin C) Use of crystal violet as a primary stain D) All of the above Answer: D) All of the above Rationale: Gram staining differentiates bacteria by the chemical and physical properties of their cell walls by staining, decolorization, and counterstaining. 2. True/False: Endospores can be stained using the standard Gram staining procedure. Answer: False Rationale: Endospores are resistant to staining due to their tough outer covering; special staining techniques such as the Schaeffer-Fulton method are required.