* Photosynthesis is the process by which plants and some other organisms use sunlight, water, and carbon dioxide to create their own food (sugar).

* Trees are plants and therefore perform photosynthesis.

* Tigers are animals and do not perform photosynthesis. They get their energy by eating other organisms.

* Mushrooms are fungi, which are decomposers. They get their energy by breaking down dead organic matter, not through photosynthesis.