Viral Biology and Characteristics

Statement 1 is correct: Viruses are obligate intracellular parasites that lack their own metabolic machinery and enzymes for energy generation. They depend entirely on host cell machinery. Statement 2 is incorrect: Viruses cannot be cultured in purely synthetic media - they must be cultured in living cells (cell cultures, animal tissues, or organisms) because they require host cellular machinery for replication. Statement 3 is incorrect: Viruses are transmitted not only by biological vectors but also through direct contact, respiratory droplets, contaminated food/water, blood transfusion, sexual contact, and mechanical means. > Viruses are obligate intracellular parasites lacking metabolic enzymes and requiring living host cells for culture and replication, with multiple transmission routes beyond biological vectors. Answer: (a).