Which of the following statements is/are correct? 1. Viruses lack enzymes necessary for the generation of energy. 2. Viruses can be cultured in any synthetic medium. 3. Viruses are transmitted from one organism to another by biological vectors only. Select the correct answer using the codes given below.

Viruses are acellular, microscopic entities that are inert in the extracellular environment [1]. They lack the cellular machinery and metabolic enzymes necessary for independent energy generation, such as ATP synthesis, and must rely entirely on a living host cell's metabolic processes to replicate [2]. Consequently, viruses cannot be cultured in synthetic, cell-free media; they require living host cells, such as cell cultures or embryonated eggs, for growth. Regarding transmission, viruses are not limited to biological vectors. They can be transmitted through various modes including direct contact (skin-to-skin), droplet spread (sneezing), airborne particles, and mechanical vectors (where the agent is carried without infecting the vector itself) [4]. Therefore, only statement 1 is correct.

Sources

1. [1] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 2: The Invisible Living World: Beyond Our Naked Eye > Ever heard of ... > p. 17
2. [2] Science , class X (NCERT 2025 ed.) > Chapter 5: Life Processes > ATP > p. 88
3. [3] https://www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/virus-transmission
4. [4] https://archive.cdc.gov/www_cdc_gov/csels/dsepd/ss1978/lesson1/section10.html