PHOTOSYNTHESIS

PHOTOSYNTHESIS LESSON

Directions:

Print the Photosynthesis reading comprehension passage and questions (see below).

Students should read the passage silently, then answer the questions.

Lesson Excerpt

Photosynthesis is one of the most important natural processes that occur. It is also one of the hardest processes to understand. If you are not sure what exactly photosynthesis is do not be alarmed. Many people have an idea of what it is though they do not know what the process does specifically.

In its most simple definition photosynthesis is the chemical process which changes chemicals and nutrients into food. This definition sums up the entire process nicely. However, the actual reaction that occurs is much harder to explain.

Plants are not the only species that use photosynthesis. Algae and even various forms of bacteria use the process to convert chemical energy into food as well. Any species that uses photosynthesis to produce food is called a phototroph. The chemical energy is most often produced by sunlight. This is why sunlight is important to the survival of plant life.

Water is also necessary for photosynthesis to occur. You probably already know that when you water a plant the water is absorbed through its roots. The water travels through the roots up long tubes that lead from the roots to other parts of the plant. These tubes are called xylem.

As animals breathe in oxygen they release carbon dioxide into the air. The plants take in the carbon dioxide that has been exhaled. Essentially, they recycle the carbon dioxide, using it for the process of photosynthesis. A plant has tiny openings called stomata. Stomata are located in the leaves of the plant. Carbon dioxide is taken into the plant through these openings. (continued...)