Green plants, algae, and certain bacteria are all part of which trophic level

The answer is: Producers.

The first trophic level belongs to producers. Producers are organisms able to produce their own food. They are autotrophs. Green plants, algae, and certain bacteria produce their own food using photosynthesis or, in some exceptions, chemosynthesis. Therefore, they are all part of producers (the first trophic level).