They aren’t. Apart from DNA replication, transcription, and translation, their genome lacks elements encoding for even the most simple metabolic pathways.
Then where are they getting the materials to replicate? Where are they getting the energy? Magic? No, they're pulling pre-metabolized materials and energy from the host.
They aren’t. Apart from DNA replication, transcription, and translation, their genome lacks elements encoding for even the most simple metabolic pathways.