Respuesta :
The autotroph in a microscopic model of a freshwater ecosystem will be
algae.
What are Autotrophs?
These are organisms which are capable of manufacturing their own food
and serve as food sources for other types of organisms such as animals.
They are mainly plants and a common example is algae.
Algae produces its food through photosynthesis which makes it an
autotroph in the ecosystem.
Read more about Autotrophs here https://brainly.com/question/16989903