Eubacteria are classified by which of the following criteria?

• A. Number of mitochondria
• B. Ability to perform photosynthesis
• C. Cell wall composition and Gram staining
• D. Presence of a nuclear envelope

Answer: (C)

Verified step by step guidance

1. Understand that Eubacteria are a large group of bacteria characterized by specific cellular features.
2. Recall that mitochondria and nuclear envelopes are organelles found in eukaryotic cells, not in bacteria, so these criteria are not used for classifying Eubacteria.
3. Recognize that the ability to perform photosynthesis is a metabolic trait, but it is not the primary basis for classifying Eubacteria as a whole.
4. Focus on the cell wall composition, which varies among bacteria and is a key factor in classification, especially when combined with Gram staining results.
5. Know that Gram staining differentiates bacteria based on the structure of their cell walls, dividing them into Gram-positive and Gram-negative groups, which is fundamental in classifying Eubacteria.