Simplify the following text for a Grade 12 native English-speaking person.
Original: Most DNA viruses are entirely dependent on the host cell 's DNA and RNA synthesising machinery , and RNA processing machinery ; however , viruses with larger genomes may encode much of this machinery themselves .
Simplified: Most DNA viruses are entirely dependent on the host cell 's DNA and RNA synthesising machinery , and RNA processing machinery . Viruses with larger genomes may encode much of this machinery themselves .