All organisms need food and utilize it to get energy for growth and maintenance of their body. Food provides nutrition to the living beings. Green Plants synthesize food for themselves by the process called Photosynthesis.The plants make their own food by themselves and hence are called autotrophs.
Nutrition is the mode of making food by an organism and its utilization by the body. The mode of nutrition in which organisms make food themselves from simple substances is called autotrophic nutrition. Animals and most other organisms take in food prepared by plants. They are called heterotrophs.
What is Photosynthesis?
An easy question, to which the answer always varies from person to person. Photosynthesis is the process by which green plants make their food with the help of water, chlorophyll and carbon-dioxide in the presence of Sunlight. Photo synthesis is the light combining with chemicals of plant for making food for them as well as the animals. It is a unique process on the Earth. It may be called the magic of plants. Sun the ultimate source of energy needs plants for synthesizing energy out of it. The leaves of the plants contain green pigment called Chorophyll. This chlorophyll helps leaves capture the energy of the sunlight. The energy is used to synthesize food from carbon dioxide and water. Since the photosynthesis of food needs the presence of sunlight, it is called Photosynthesis.
The green plants are called Autotrophs. Plants make their own food by themselves and hence are called autotrophs. Plants synthesize carbohydrates through the process called Photosynthesis. All the green plants which make food are called autotrophs.
All plants aren’t green. Some of them are violet, red or yellow. It means that they don’t have green pigments in them. then how do they make their food? Cuscuta (Amar-bel)is an example of such plant. Such plants depend on others for their food. They depend on food made by other green plants and hence are called Heterotrophs. They use the Heterotrophic mode of Nutrition. The insectivorous plants like Pitcher plant is also one of the examples of Heterotrophs. All the animals are also Heterotrophs.
Some organisms take in nutrients from dead and decaying matters. Such organisms are called and Saprotrophs, and their mode of nutrition is called as Saprotrophic Nutrition. Fungi and Mushrooms are some examples of Saprotrophs.
1. Autotrophic– It is the mode of nutrition adopted by green plants. In this type of nutrition the organisms make their food by themselves from simple substances.
2. Chlorophyll- Chlorophyll is the green pigment present in green plants which helps plants to capture energy from the Sunlight.
3. Heterotrophs- The living organisms which depend on others for their food and cannot prepare their own food by themselves are called Heterotrophs.
4. Host- Those organisms are called hosts which allow other organisms to live on themselves and depend on them for their nutrition. The hosts get deprived from their nutrition due to the other organisms living on them.
5. Insectivorous- Insectivorous means those organisms which feed on insects for getting nutrition. The Pitcher plant is an example of Insectivorous plant.
6. Nutrient- Carbohydrates, Oils, fats, Proteins, Vitamins and minerals are the nutrients of the nutrients that we get from our food.
7. Nutrition- Nutrition is the way through which we utilize our food get energy for growth and maintenance of our body.
8. Parasite- It is that organism which lives on other organism’s body and depends on it for it’s food. parasite deprives the nutrition of it’s host by feeding on it. Cuscuta is a parasite.
9. Photosynthesis- The process through which plants make their own food by themselves with the help of Carbon-dioxide, Chlorophyll and water in the presence of Sunlight.
10. Saprotrophs- Those organisms which take nutrients from dead and decaying matters are called Saprotrophs.
11. Saprotrophic Nutrition– the mode of nutrition in which the nutrition is extracted from dead and decaying organisms is called Saprotrophic nutrition.
12. Stomata – Stomata are the tiny pores in the leaves of the plants which enable plants to breathe and remove excess water from their bodies.
Why do organisms take food?
Answer- All organisms take food to get energy for their growth, and maintenance of their body.
2. Distinguish between a parasite and a Saprotroph?
Answer-
Parasite | Saprotroph |
Parasite feeds on other living organism. | Saprotroph feeds on dead and decaying organisms and matter |
Eg.- Cuscuta, Leeches | Eg.- Mushroom, Fungi |
3. How would you test the presence of Starch in leaves?
Answer- Starch test can be performed on boiled leaf. If the leaf turns blue- black in color on pouring iodine solution on it, it means that leaf contains starch in it. And always the leaf changes its color to blue- black.
4. Give a brief description of process of synthesis of food in green plants.
Answer- During photosynthesis, chlorophyll containing cells of leaves, use carbon-dioxide and water in the presence of sunlight to synthesize carbohydrates.
5. Show with the help of a sketch that the plants are the ultimate source of food?
a) Amarbel is an example of – parasite.
b) The plant which traps and feeds on insects is – pitcher plant.
Column I | Column II |
Chlorophyll | Leaf |
Nitrogen | Bacteria |
Amarbel | Parasite |
Animals | Heterotrophs |
Insects | Pitcher plant |
a) Carbon-dioxide is released during Photosynthesis. (F)
b) Plants which synthesize their food by themselves are called Saprotrophs. (F)
c) The product of Photosynthesis is not a protein.(T)
d) Solar energy is converted into Chemical Energy during Photosynthesis. (T)
11. Choose the correct option:
a) Which part of the plant gets carbon-dioxide from air for Photosynthesis- Stomata
b) Plants take carbon-dioxide from the atmosphere mainly through their: Leaves