Defective Viruses

**Definition:** Viruses which lack a complete genome so that they cannot completely replicate or cannot form a protein coat. Some are host-dependent defectives, meaning they can replicate only in cell systems which provide the particular genetic function which they lack. Others, called SATELLITE VIRUSES, are able to replicate only when their genetic defect is complemented by a helper virus.

**Tree numbers:** - B04.265

**Synonyms:** - Incomplete Viruses - Defective Hybrids