Final answer:
Organisms that cannot synthesize their food are known as heterotrophs, which must consume or absorb nutrients from other organisms. Autotrophs, in contrast, can produce their food and are crucial for ecosystem stability. Protists that feed on dead organic material are called saprobes.
Step-by-step explanation:
Organisms that cannot produce or synthesize their food are called b) Heterotrophs. These organisms, known as consumers, must absorb or consume food from other organisms. This includes all animals, most protists, fungi, and many bacteria. On the other side, we have autotrophs, like plants and certain bacteria, which are dubbed producers because they can create their food and are essential for the stability of ecosystems.
Protists that absorb nutrients from dead organisms are a specific type of heterotroph called c) saprobes. They play an important role in decomposing organic matter and recycling nutrients within an ecosystem. Understanding the role of autotrophs and heterotrophs is crucial to appreciating the flow of energy and nutrients through food webs.