It’s silly to think about a plant sitting down at the dinner table and enjoying a meal, but plants need food just like all of us. They just obtain their food in a different way than you and I do. Plants are called autotrophs because they can use energy from light to synthesize, or make, their own food source. This process is known as photosynthesis and takes place inside the chloroplast of plant cells. The word photosynthesis comes from two root words: photo meaning light and synthesis meaning to make. In order for photosynthesis to take place, plants need three reactants, or materials to start the reaction: carbon dioxide, water, and radiant energy from the sun. Carbon dioxide enters the plant through tiny openings on the underside of leaves called stomata. The stomata are surrounded by specialized cells called guard cells that open and close the stomata to regulate how much carbon dioxide enters a plant, plus control how much water and oxygen leave a plant.
Plants also require water to make their own food. Water typically enters the the plant through the roots and travels upward to the stem and leaves.
Last, plants require radiant (light) energy from the sun, which drives the process of photosynthesis. This light energy is trapped by the green chlorophyll found in the chloroplasts of plant cells.
The energy from light causes a chemical reaction that breaks down the molecules of carbon dioxide and water. The atoms are reorganized to make the products of sugar (glucose) and oxygen gas. Plants use glucose for chemical energy for their growth and repair. The oxygen that is produced is released back into the ecosystem through the stomata.

Read the article above, then answer these questions.

2. The main idea is:
a) plants need three reactants for photosynthesis to take place b) plants need food just like all of us
c) oxygen that is produced is released back into the ecosystem d) plants use energy from light to make their own food

3. All of the following are reactants of photosynthesis except:
a) oxygen
b) carbon dioxide c) water
d) radiant energy