Final answer:
Autotrophs are synonymous with producers, as they can produce their own food from inorganic materials using sunlight or chemical energy. Humans are considered heterotrophs and omnivores, depending on their diet in the food chain. Protists that feed on decaying organisms are called saprobes.
Step-by-step explanation:
The term autotroph can be synonymous with the term producer. Autotrophs are organisms that can produce their own food using energy directly from the sun or from chemical bonds. These organisms, commonly called producers, are vital to ecosystems because they can convert inorganic compounds into organic molecules that are necessary for life.
Humans, among other organisms, are considered heterotrophs. A heterotroph is an organism that cannot produce its own food and instead obtains energy by consuming other organisms. Humans fall under the categories of heterotroph, omnivore (because they consume both plant and animal matter), and primary consumer or tertiary consumer depending on the food chain context.
Protists that absorb nutrients from dead organisms are known as saprobes.