Question

Select the right reason why antibodies not effective against the virus.

• A. Viruses lacks DNA
• B. Viruses lacks RNA
• C. Viruses lacks host
• D. Viruses lacks ribosomes

Hint:

Antibiotics mainly target:
• Bacterial ribosomes
• Bacterial cell wall Viruses lack these structures.

Answer 1

The Correct Option is D

Concept: Viruses are obligate intracellular parasites. They depend completely on host cellular machinery because:
• They do not possess ribosomes. Without ribosomes:
• Viruses cannot synthesize proteins independently.

Step 1: Understand viral structure. Viruses generally contain:
• Genetic material (DNA or RNA)
• Protein coat However they lack:
• Cytoplasm
• Cell organelles
• Ribosomes

Step 2: Understand why antibiotics are ineffective. Antibiotics generally act on:
• Bacterial ribosomes
• Cell wall synthesis
• Bacterial metabolism Since viruses do not possess: \[ \boxed{ \text{Ribosomes} } \] many antibiotics cannot act effectively on them.

Step 3: Analyze options carefully.
• Viruses may contain either DNA or RNA, so options A and B are incorrect.
• Viruses do require host cells, therefore option C is incorrect.
• Viruses lack ribosomes, which explains ineffectiveness of many antibiotics. Hence correct option is: \[ \boxed{ \text{Viruses lack ribosomes} } \]

Step 4: Choose correct answer. Thus correct option is: \[ \boxed{(4)} \] Final Conclusion: Viruses lack ribosomes and therefore antibiotics targeting ribosomes are generally ineffective. Hence correct answer is: \[ \boxed{(4)} \]