Which of the following characteristics can be utilized to classify and categorize viruses?

• A. Type of nucleic acid (DNA or RNA)
• B. Presence of a cell wall
• C. Ability to perform photosynthesis
• D. Mode of sexual reproduction

Answer: (A)

Verified step by step guidance

1. Understand that viruses are unique infectious agents that differ significantly from cellular organisms, so traditional classification methods based on cellular structures or metabolic capabilities often do not apply.
2. Recognize that viruses can be classified based on their genetic material, which is either DNA or RNA, and this is a fundamental characteristic used in viral taxonomy.
3. Note that viruses do not have a cell wall, so the presence or absence of a cell wall is not a useful characteristic for classifying viruses.
4. Acknowledge that viruses lack the machinery for photosynthesis, so the ability to perform photosynthesis is irrelevant for viral classification.
5. Understand that viruses do not reproduce sexually; instead, they replicate by hijacking the host cell's machinery, so mode of sexual reproduction is not a criterion for viral classification.