Which of the following statements is/are correct?

Correct Answer: A) Viruses lack enzymes necessary for the generation of energy. Viruses are obligate intracellular parasites, meaning they can only replicate inside a host cell. They lack the machinery for independent metabolic processes, including energy generation. They rely entirely on the host cell's enzymes and metabolic pathways for their survival and replication. Let's analyze why other options are incorrect: B) Viruses can be cultured in any synthetic medium. This is incorrect. Viruses require living host cells for replication and cannot be cultured in a typical synthetic medium like bacteria or other organisms. They need the complex environment and machinery of a living cell. C) Viruses are transmitted from one organism to another by biological vectors only. This is incorrect. While many viruses *are* transmitted by biological vectors (e.g., mosquitoes transmitting dengue virus), they can also be transmitted through direct contact, airborne droplets, contaminated surfaces, and other means. Not all viruses require vectors. D) 1, 2 and 3 Since options B and C are incorrect, this option is also incorrect.