Answer: Algae, trees, turtles, and fish are biotic factors
Explanation: Biotic factors refer to living (or formerly living) factors within an ecosystem. Therefore, all of the plants, animals, fungi, bacteria, and protists that live within an ecosystem are considered biotic factors. Biotic factors also include objects within an ecosystem that were formerly alive, such as the wood of a fallen tree or the carcass of an animal. Thus, algae, trees, turtles, and fish are all biotic factors since all of these organisms are alive and capable of reproduction.
On the other hand, abiotic factors refer to the aspects of an ecosystem that are not alive. Examples include water, the air, soil, temperature, and rocks. Therefore, soil and temperature are considered abiotic factors rather than biotic factors because neither of these things are considered living.