Green plants CLASS IV

CLASS 4 GREEN PLANTS
OWNER:DEEPA UNNIKRISHNAN

1. THE GREEN PLANTS The green coloUr of plants is caused by a pigment called chlorophyll. Chlorophyll has the ability to absorb light energy from the sun. The energy that is absorbed is used to force reactions with water and carbon dioxide. The result of these reactions is the production sugar and oxygen

2. LEAF

3. STOMATA Stomata is found at the lower s ide of the leaf. Leaves make food for the plant. So they are the food factory of a plant. Leaves help the plant to let gases in and out through stomata.

4. The food making process - Photosynthesis SUNLIGHT + CARBON DIOXIDE + WATER +MINERALS + CHLOROPHYLL SUGAR + OXYGEN + WATER VAPOUR

5. HOW IS THE FOOD STORED BY PLANTS The food prepared by the plants (glucose) is transported by the all parts of the plant. The plant uses some of its food for its daily activities and stores extra food as STARCH in different parts of the plant. Plants Storage of food Sugar cane and Potato Stem Beetroot and Carrot Root Spinach and Lettuce Leaf Broccoli and Cauliflower Flower Mango and Apple Fruit Coffee and Gram Seed

6. Starch test To test the presence of starch on potato we need :- Slice of a potato Iodine Dropper The iodine solution turns the colour of potato into bluish black . This shows that potato has a lot of starch stored in it .

7. Activity to show that LIGHT is needed by leaves for photosynthesis. Keep the healthy potted plant in a dark room for two days. 2) Pluck a leaf from the plant and boil it in the water and dip the leaf in hot alcohol. Then wash it in cold water. 3 ) Put a few drops iodine solution on the leaf. 4) The colour of the leaf does not change. This shows that no starch has formed on the leaf in the absence of light.

8. INTERDEPENDENCE OF PLANTS AND ANIMALS Plants and animals are dependent on each other in many ways . Green plants are the main producers of food. Animals depend on these plants for their food. Thus a food chain is formed. A chain that shows a series of organisms where each member depends on the lower member in the series for food is called a food chain.

9. Interdependence of plants and animals in a food chain helps to maintain a balance between the number of plants and animals. So if there is a sudden increase or decrease in the number of either plants or animals, the balance in nature will be disturbed . Other than that, plants also give out oxygen which is needed by animals to breathe. Animals give out carbon dioxide , which is used by the plants for Photosynthesis .