Explanation:

- Photosynthesis: This process is used by plants and some bacteria to convert light energy into chemical energy. Amoebas do not perform photosynthesis as they are not plants.

- Diffusion: A passive process where molecules move from high to low concentration. Amoebas may absorb small molecules through diffusion but not acquire their main food through it.

- Endocytosis: Amoebas use this process to engulf food particles. They extend their cell membrane around the particle to form a food vacuole.

- Exocytosis: This is the process of expelling materials from the cell. Amoebas use this to remove waste rather than acquire food.