Plants: The Lungs of the Earth

Tree

The service provided by plants for the sustenance of the biological world is unique. Plants are the cheapest and effective natural mechanisam for the purification of air.plants offer great service to the biological world by absorbing carbon dioxide from the atmosphere and releasing oxygen.it is estimated that plants give out approximately 118 kilograms of oxygen when they use one tonne carbon dioxide.As the plant cover on the earth decreases, this recycling mechanism stops and air pollution become severe.observe the pictures. Based on the indicators prepare a note on the importance of plants.

                                     

Tree

A tree typically has many secondary branches supported clear of the ground by the trunk. This trunk typically contains woody tissue for strength, and vascular tissue to carry materials from one part of the tree to another. For most trees it is surrounded by a layer of bark which serves as a protective barrier. Below the ground, the roots branch and spread out widely; they serve to anchor the tree and extract moisture and nutrients from the soil. Above ground, the branches divide into smaller branches and shoots. The shoots typically bear leaves, which capture light energy and convert it into sugars by photosynthesis, providing the food for the tree's growth and development.

                               

Tree