Strategies for writing an effective introduction. Start by thinking about the question (or questions) you are trying to answer. Your entire essay will be a response to this question, and your introduction is the first step toward that end.
A: Plants release oxygen as a by-product of photosynthesis, a process in which carbon dioxide is converted into sugar. The sugar is then used as an energy source for the plant. When oxygen is produced through photosynthesis, it is released by the plant into the atmosphere. The sugars produced by photosynthesis are utilized by combining them with oxygen through a process called oxidation. Photosynthesis chemically converts sunlight into energy after being collected by special cells in their leaves known as chloroplasts.
What plants need. How plants breathe. Just like people, plants need air in order to live. Human beings use lungs to breathe in a gas called oxygen and breathe out a gas called carbon dioxide. Without our lungs, we couldnât survive. Plants on the other hand, use their leaves and roots to breathe in carbon dioxide and turn it into clean, pure oxygen that humans and animals then breathe. If it werenât for plants, we wouldnât have enough oxygen!