The food-making process in a plant is called photosynthesis because it involves using light (photo) to create food (synthesis).

Here's a breakdown:

* Photo comes from the Greek word "phos," meaning light.

* Synthesis refers to the process of combining simple substances into more complex ones.

In photosynthesis, plants use light energy from the sun to convert carbon dioxide (CO2) and water (H2O) into glucose (a type of sugar) and oxygen (O2). This glucose is the plant's food source, providing it with energy for growth and other life processes.

So, the term "photosynthesis" perfectly describes the process: plants use light to synthesize their food.