The correct statement is:

1 only: Viruses lack enzymes necessary for the generation of energy.

Explanation:

1. Viruses are obligate intracellular parasites that lack their own metabolic machinery. They rely on the host cell`s enzymes and resources for energy production and replication.

2. Viruses require a host organism to replicate and cannot be cultured in synthetic media alone. They need living cells to provide the necessary machinery for replication.

3. Viruses can be transmitted from one organism to another by various means, including biological vectors (such as mosquitoes, ticks, and other organisms), but they can also be transmitted through direct contact, respiratory droplets, contaminated surfaces, and other mechanisms.

Therefore, the correct answer is:

1 only.