Which type of microorganisms require living matter for their growth?

The correct answer is that parasites require living matter for their growth. Parasites are organisms that live on or in a host organism, deriving nutrients at the host's expense. They are dependent on a living host to survive and reproduce, relying on the host's biological processes for sustenance. This dependence on a living system distinguishes them from other types of microorganisms.

Pathogenic microorganisms can also depend on living hosts to damage tissues or cause disease, but the term "pathogenic" encompasses a broader range of harmful organisms that may not require a living host for all life stages. Saprophytes, on the other hand, thrive on dead organic matter and do not require living organisms for their growth. Viruses are unique in that they can only replicate within a living host cell and are technically not categorized as living organisms until they are inside the host, making their requirements for growth somewhat different from that of true parasites.