Photosynthesis in Green Plants.

What do plants and animals need to grow?

Almost all plants and animals need air, water, light, and nutrition to grow. Green plants use a complicated chemical process, called photosynthesis, to create energy for survival and growth. Since plants create their own energy, they are the first link in the food chain. Animals need to drink water and eat plants or other animals to get energy. Therefore, they are present at the next step in the food chain. There are some animals, like camels, that can survive for days without drinking water. Since they live in deserts with very little water, they have adapted to the special conditions of their habitat.

How do plants get food?

Unlike animals, plants produce their own food. Green plants use water, nutrients, sunlight, carbon dioxide and green pigment in their leaves called "chlorophyll" to produce their food. Normally water and nutrients are absorbed from the ground through their roots. Some plants, however, have developed other methods for obtaining water and nutrients. Many plants make funnel-shaped 'containers' with their leaves to catch water.

What happens when we keep plants in the dark?

In the absence of light, plants shed their leaves and die, leaving only their roots and stems. Plants grow slowly at night and in winters. Most animals are also dependent on light, although some have adapted to their dark habitats. For example, the moles living below the ground are almost blind because they do not need their eyes underground. We humans also need sunlight to help produce vitamin D in our skin, which in turn is needed for building bones.

What is photosynthesis?

"Photosynthesis is the process of making food by green plants by the use of water and carbon dioxide in the presence of sunlight and chlorophyll".

The chloroplast inside the green leaves of plants is the 'workshop' where photosynthesis takes place. Water is supplied to the leaves by the roots, and carbon dioxide is absorbed from the air through tiny pores on the lower side of the leaf and thus these tiny pores are known as "Stomata". Both these are broken down into the elements hydrogen, carbon, and oxygen with the help of chlorophyll and sunlight. Plants build "Glucose"(grape sugar) from these elements and oxygen is released in the atmosphere as a by-product. Photosynthesis has been the source of oxygen in the air since the origin of life on the Earth.

In nature, there are 'producers' that build the biological mass and 'consumers' that eat. Producers are the plants, which grow and create energy with the help of photosynthesis that is "Green Plants".