Plants have a direct relationship with the lives of people. This is because plants are helpful and provide important requirements for people to live and as a result we can draw the conclusion that without plants people could not live (Wisconsin & Office of Endangered and Nongame Species, 1979). In their research they established that the most important thing about plants is that plants supply oxygen. Wisconsin & Office of Endangered and Nongame Species (1979) established that “when people breathe in oxygen their lungs change it into gas called carbon dioxide, and on the other people breathe out carbon dioxide when they exhale while plants breathe in carbon dioxide and change it to oxygen” (p. 18). Therefore when plants exhale they provide people with the oxygen that people need to survive.
Caduto & Bruchac (1997) indicated that green plants are ultimately the source of energy for nearly all living things including people. It is important to note that energy for growth of green plants comes from the sun which occurs during a crucial process known as photosynthesis. According to Caduto & Bruchac (1997) photosynthesis occurs “when sunlight strikes the green chlorophyll of the leaf changing water and carbon dioxide into simple sugars, starches, fats, proteins, vitamins and other nutrients that trap the suns energy” (p.63). In the process oxygen is produced which is a vital gas used by people during respiration to metabolize their food to get energy for growth and maintenance. Caduto & Bruchac (1997) also indicated that “plants also provide people with food, shelter and oxygen, since people take in oxygen and give off carbon dioxide during respiration, while plants use carbon dioxide and produce oxygen during photosynthesis” (p. 63).
Another important thing about the relationship between plants and people according to Wisconsin & Office of Endangered and Nongame Species (1979) is that plants provide people with food to eat. They continue to say that many plants have edible parts such as vegetables, fruits and plants seeds. Some of the plant seeds which are edible include maize, beans and peanuts while some of the edible plant leaves include spinach and cabbage. Besides the above advantages plants are also used for manufacturing medicines used to cure most diseases found in people (Wisconsin & Office of Endangered and Nongame Species 1979).
There are six steps which indicate how plants acquire carbon dioxide and release oxygen into the atmosphere which is then used by human beings. According to Wisconsin & Office of Endangered and Nongame Species (1979) carbon dioxide from the air comes in through tiny holes in the leaf (stomates) and water goes from the roots to the leaves. The third step is that the chlorophyll in the leaves traps the energy from sunlight which helps in the changing of the water to hydrogen and oxygen. The fifth step is that hydrogen joins with carbon dioxide and produces food for the plant and finally oxygen gas is released from the leaf through stomates and then used by people and other animals for respiration (Wisconsin & Office of Endangered and Nongame Species, 1979).
Plants can grow in an air tight box with everything else provided for the growth of the plant expects oxygen. This is because plants do not need oxygen to do the process of photosynthesis in which plants manufacture their food. The most important thing is that sunlight should be present for this plant to grow in this box. With carbon dioxide, water, and sunlight present in the airtight box the plant will grow provided that there is a way in which the oxygen produced in the air tight box is released to minimize its concentrations and allow a good circulation of carbon dioxide which is vital for the growth of the plant. The airtight box should be able to allow sunlight to penetrate because energy from the sunlight is used to combine carbon dioxide from the air and water from the soil to make the important nutrients required for the growth of the plant (Wisconsin & Office of Endangered and Nongame Species, 1979).