PLANTS
All green plants use the energy of sunlight to make sugary carbohydrate food from water and carbon dioxide in the air. This is why they grow well only in sunlit, moist places. The food fuels growth and is used to make cellulose — the tough, fibrous tissue that helps support all the various parts of the plant, from its stems and leaves to its flowers.
- GERMINATION A bean plant begins life as a seed with two halves, called cotyledons. In spring when the weather is mild, the seed starts to absorb water through a minute hole in its outer coating (the testa). The seed swells and about three days later a root grows to hold the plant in place, and a shoot appears above the ground. This process is called germination.
- ROOTS The plant’s roots absorb water from the soil. The water is used by the leaves to make food. The water also contains dissolved mineral salts, such as nitrates and phosphates, which are essential for growth.
- STEM The strong stem of the plant supports its leaves in the sunlight. It also contains bundles of tubes or veins. These allow water containing dissolved nutrients to flow up from the roots to the leaves, and also carry sugary food from the leaves to other parts of the plant.
- LEAVES The leaves are the plant’s food factories. They act like solar panels, as the green chlorophyll enables the plant to absorb the energy of sunlight and use it for photosynthesis – the process in which the plant takes carbon dioxide from the air, and combines it with water drawn up by the roots to make sugar. Oxygen is also produced in the process and released into the air.
- TRANSPIRATION As sunlight warms a plant; water in the leaves is lost as water vapour, through pores called stomata. The leaves then take in water from the stem, which in turn draws more water up into the plant from the roots. The water carries nutrients from the soil with it.
Picture Credit : Google
