Final answer:
Fungi are heterotrophic, as they absorb nutrients from their environment by decomposing organic matter, unlike plants which are typically autotrophic, and they are not capable of photosynthesis or mixotrophy.
Step-by-step explanation:
The mode of nutrition used by fungi is heterotrophic. Fungi obtain their nutrients by breaking down organic matter. Unlike plants, they cannot perform photosynthesis (photosynthetic) to produce their own food. Fungi are not autotrophic (capable of generating their own food from inorganic substances using light or chemical reactions) nor are they mixotrophic (capable of both photosynthesis and heterotrophy). Rather, they are similar to animals in that they absorb nutrients from their environment. They do this by secreting enzymes to decompose complex organic substances into simpler ones, which they then absorb. This mode of nutrition classifies them as saprobes or decomposers within an ecosystem.