NUTRITION IN PLANTS (CH-1) ************************* LIFE PROCESSES: The basic activities like nutrition, respiration, growth, repair and replacement of damaged body cells or tissues, excretion, reproduction and response to stimuli etc., which all living organisms perform are called life processes. METABOLISM: The sum of all the life processes is called Metabolism. ANABOLISM: The sum of constructive life processes like photosynthesis is called Anabolism. CATABOLISM: The sum of all destructive life processes like respiration is called Catabolism. NUTRITION: The process of intaking or consumption and utilization of food is called nutrition. NUTRIENTS: The micro components of the food like Proteins, Carbohydrates, fats, vitamins and minerals etc. necessary for our body are called Nutrients. CELL: The bodies of living organisms are made of tiny units called cells. CELL MEMBRANE: The cell is enclosed by a thin outer boundary, called cell membrane. NUCLEUS: A spherical structure located in the centre of the cell is called nucleus. CYTOPLASM: The nucleus is surrounded by a jelly-like substance called cytoplasm. RHIZOBIUM: A bacterium which can not prepare its own food. It lives in the roots of leguminous plants. It takes atmospheric nitrogen and converts it into a soluble form. HAUSTORIA: To absorb food from the host, the parasites produce special structures called haustoria. MOULD: A non green plant. BREAD MOULD: A non-green plant grows on the breads is called bread mould.
EXAMPLE OF SAPROTROPHS: Fungi, mushrooms, yeast and many bacteria are saprophytic in nutrition or saprophytes ( also saprotrophs) TOTAL PARASITES: Dodder, amarbel (cuscuta) PARTIAL PARASITES: Mistle-toe SYMBIOTIC: Lichen PARASITE: Organism that derives its food from the living body of another organism is called parasite. HOST: The organism from which parasite derives its food is called host. SAPROPHYTE: Organism which derives its food from dead and decaying plants and animals is called Saprophyte.
NCERT BOOK QUESTIONS Q.1. Why do living organisms need to take food? Ans. Food is essential for all living organisms. . To perform life processes such as respiration, growth, repair and replacement of damaged body cells or tissues, excretion, reproduction and response to stimuli etc., all living organisms require a continuous supply of energy and materials which are obtained from the micro components such as protein, carbohydrates, fats, vitamins and minerals called nutrients present in the food.. Hence, all living organisms need to take food.
Q.2 Distinguish between a parasite and a saprotrophs. See the extra questions. Q.3. How do you test the presence of starch in leaves. See the extra questions. Q.4. Give a brief description of the process of synthesis of food in green plants. Ans. Photo means ‘light’ and synthesis means ‘to combine’. Literally, photosynthesis means ‘synthesis in the presence of light’. It is a unique and the most important process by which plants synthesize their own food from simple inorganic substances like carbon dioxide (CO2) and water (H2O) in the presence of sunlight and chlorophyll. Carbon dioxide (CO2) is absorbed from the atmosphere through stomata present on the lower surface of the leaves and water is absorbed from the soil through the root system and transported to the leaves by xylems .The chlorophyll contained in the cells of the leaves traps the solar energy. Then photosynthesis takes place in the leaves. During photosynthesis because of the intracellular chemical reaction of carbon dioxide and water in the presence of sunlight and chlorophyll, carbohydrates are prepared and oxygen is released out. Hence, Oxygen is a photochemical by product of photosynthesis. The primary function of photosynthesis is to capture light energy, convert some of this light energy into chemical energy, and store this chemical energy in molecules of carbohydrates which are ultimately get converted into starch. The chemical equation of Photosynthesis is as under.
Sunlight
CO2 + H2O ----------------------→ C6 H12 O6 + O2 ↑ Carbon dioxide Water Chlorophyll Carbohydrates Oxygen (Glucose)
Q.6. Fill in the blanks a) Green plants are called autotrophs since they synthesize their own food. b) The food synthesized by the plants is stored as starch. c) In photosynthesis solar energy is captured by the pigment called stomata. d) During photosynthesis plants take in carbon dioxide and release oxygen.
Q.7. Name the following i) A parasitic plant with yellow, slender and tubular stem : Amarbel (Cuscuta) ii) A plant that has both autotrophic and heterotrophic mode of nutrition: Pitcher plant iii) The pores through which leaves exchange gases: Stomata
Q.8. Tick the correct statement a) Amarbel is an example of i) Autrophs ii) Parasites ii) Host b) The plants which traps and feeds on insects i) Cuscuta ii) China Rose iii) Pitcher plant iv) Rose Q.9 Match the following Chlorophyll Leaf Nitrogen Bacteria Amarbel Parasite Animals Heterotrophs Insects Pitcher plant
Q.10. True or False i) Carbon dioxide is released during photosynthesis FALSE ii) Plants which synthesize their food themselves are called saprotroph. FALSE iii) The product of photosynthesis is not a protein. TRUE
ii) Solar energy is converted into chemical energy during photosynthesis. TRUE Q.11. Choose the correct option from the following. Which part of the plant takes in carbon dioxide from the air for photosynthesis. a) Root hair b) Stomata c) leave veins d) Sepals
Q.12. Choose the correct option from the following Plants take carbon dioxide from the atmosphere mainly from their : a) Roots b) Stems c) Flowers d) Leaves
Extra : The Autotrophic organisms are the producers in an ecosystem. The heterotrophic organisms are the consumers in an ecosystem.
EXTRA QUESTIONS:
Q.1. What is the need of nutrition in plants? Ans. The process of intaking or consumption and utilization of food is called nutrition. To perform life processes such as respiration, growth, repair and replacement of damaged body cells or tissues, excretion, reproduction and response to stimuli etc., plants require a continuous supply of energy and materials which are obtained from the micro components such as protein, carbohydrates, fats, vitamins and minerals called nutrients present in the food. Hence, the plants are in great need of nutrition.
Q.2. What are the life processes in organism? Ans. The basic activities like nutrition, respiration, growth, repair and replacement of damaged body cells or tissues, excretion, reproduction and response to stimuli etc., which all living organisms perform for maintenance and continuance of their lives are called life processes. The sum of all the life processes is called Metabolism.
Q.3. What is nutrition? Ans. The process of intaking or consumption and utilization of food is called nutrition. To perform life processes such as respiration, growth, repair and replacement of damaged body cells or tissues, excretion, reproduction and response to stimuli etc., plants require a continuous supply of energy and materials which obtained from the micro components such as protein, carbohydrates, fats, vitamins and minerals called nutrients present in the food. Hence, the plants are in great need of nutrition.
Q.4. What are nutrients? Ans. The micro components of food like proteins, carbohydrates, fats, vitamins and minerals etc. necessary for our body are called Nutrients. To perform life processes such as respiration, growth, repair and replacement of damaged body cells or tissues, excretion, reproduction and response to stimuli etc., plants require a continuous supply of energy and materials which are obtained from these nutrients present in the food. Hence, the nutrients are of great importance.
Q.5. What are the different modes of nutrition? Ans. Based on the mode of obtaining food, organisms can be classified into two groups
i) Autotrophic Nutrition:- Auto means “self” and trophic means “nourishment”. The mode of nutrition in which organisms prepare or synthesize organic materials (their own food) from simple inorganic materials is called autotrophic nutrition. This mode of nutrition is found in green plants and autotrophic bacteria only because of the presence of chlorophyll which is capable of trapping and fixing the solar energy. This energy is utilized by the green plants for synthesizing their own food from simple inorganic materials like carbon dioxide and water by the process of photosynthesis. Hence, the green plants are called autotrophic organisms or autotrophs. Autotrophic organisms or autotrophs are producers of food in an ecosystem.
ii) Heterotrophic Nutrition:- Hetero means “other” and trophic means “nourishment”. The mode of nutrition in which the organisms can not prepare or synthesize their own food from simple inorganic materials because of lack of chlorophyll is called heterotrophic nutrition. This mode of nutrition is found in all animals including humans and non-green plants such as phanerogams, fungi and bacteria. In this type of nutrition energy is derived from the intake and digestion of complex organic substances (readymade food), generally plant or animal tissue. Thus, all animals including humans and the non-green plants directly or indirectly depend on plants. Hence, they are known as heterotrophic organisms or heterotrophs. Heterotrophs are consumers in an ecosystem. Depending upon the mode of living and the mode of intake of food, heterotrophs may be saprophytic, parasitic, symbiotic and insectivorous.
Q.6. Explain photosynthesis. Ans. Photo means ‘light’ and synthesis means ‘to combine’. Literally, photosynthesis means ‘synthesis in the presence of light’. It is a unique and the most important process by which plants synthesize their own food from simple inorganic substances like carbon dioxide (CO2) and water (H2O) in the presence of sunlight and chlorophyll. Carbon dioxide (CO2) is absorbed from the atmosphere through stomata present on the lower surface of the leaves and water is absorbed from the soil through the root system and transported to the leaves by xylems .The chlorophyll contained in the cells of the
leaves traps the solar energy. Then photosynthesis takes place in the leaves. During photosynthesis because of the intracellular chemical reaction of carbon dioxide and water in the presence of sunlight and chlorophyll, carbohydrates are prepared and oxygen is released out. Hence, Oxygen is a photochemical by product of photosynthesis. The primary function of photosynthesis is to capture light energy, convert some of this light energy into chemical energy, and store this chemical energy in molecules of carbohydrates which are ultimately get converted into starch. The chemical equation of Photosynthesis is as under.
Sunlight CO2 + H2O ----------------------→ C6 H12 O6 + O2 ↑ Carbon dioxide Water Chlorophyll Carbohydrates Oxygen (Glucose)
(Note : Xylem: the material in plants that carries water and minerals upwards from the root.Phloem: the material in a plant containing very small tubes that carry sugars produced in the leaves around the plant. )
Q.7. What is the importance of Photosynthesis? Ans. Photosynthesis is one of the most important characteristics of the autotrophs. It is a unique and the most important process on the earth. Due to the process of photosynthesis, plants prepare their own food (organic substance like carbohydrates) from simple inorganic substances like carbon dioxide and water. The survival of almost all living organisms directly or indirectly depends upon the food made by the food.
Secondly, oxygen which is essential for survival of all living organisms (aerobes) is a photochemical by product of photosynthesis. In the absence of photosynthesis, life would be impossible on the earth. Hence, it is of great importance.
Q.8. What are the other modes of nutrition in plants? The plants which lack chlorophyll can not prepare their own food by the process of photosynthesis. So, these plants derive their food from dead and decaying bodies or by living in or on the bodies of other living organisms. Basically, there are four methods of heterotrophic nutrition which are described below.
i) Saprophytic Nutrition: 'Sapros' refers to rotten and 'trophic' refers to food. The mode of nutrition in which non-green plants take in nutrients in solution form from dead and decaying matter is called saprophytic or saprotrophic nutrition. The saprophytic organisms secrete digestive juices that contain enzymes directly on to the food. it makes the food soluble and it is then absorbed by the organisms. Plants which use saprophytic mode of nutrition are called Saprophytes. Fungi, mushrooms, yeast and many bacteria are examples of Saprophytes or Saprotrophs. These are commonly seen during and after rains.
ii) Parasitic nutrition: The mode of nutrition in which some plants derive their food by living on another organism is called parasitic nutrition. Plants which use parasitic mode of nutrition are called parasites. The organism from which the food is derived by the parasite is called host. The parasites produce special structures called haustoria for absorbing food from the host. Parasites may be total or partial. Dodder or Amarbel (Cuscuta) is a total parasite. But Mistle-toe is a partial parasite. Though,
Mistle-toe has chlorophylls to synthesize its own food, it receives water and minerals from the host plant. So it is a partial parasite. (Note :Some animals like Plasmodium and roundworm are parasites.)
iii) Symbiotic nutrition: The mode of nutrition in which two different organisms live together, share shelter and nutrients is called symbiotic nutrition. In organisms called lichens, alga and a fungus live together. Alga contains chlorophyll and is autotroph, while fungus lacks chlorophyll and is heterotroph. So, in this type of nutrition, fungus provides shelter, water and minerals to the alga and in return, the alga provides food which it prepares by photosynthesis. This type of relationship between the plants is called symbiotic relationship.
Note: lichen : a very small grey or yellow plant that spreads over the surface of rocks, walls and trees and does not have any flowers. Alga: very simple plant with chlorophyll that grows in or near water, including seaweed. Plural of alga is “algae”. Alga is autotroph.
Fungus: any plant without leaves, flowers or green colouring, usually growing on other plants or on decaying matter. Mushrooms and mildew are both fungi. Plural of fungus is ‘fungi’.Fungus is heterotroph.
iv) Insectivorous: The mode of nutrition in which some green plants feed on small insects is called insectivorous. The plants which show this mode of nutrition is called insectivorous plants. Though the insectivorous plants are autotrophs and prepare their own food by the process of photosynthesis, they trap small insects to meet their nitrogen requirement. In insectivorous plants, the leaf, lamina or any other part of the plant is modified to trap the insects. The example of insectivorous plants is pitcher plants, venus fly-trap and sun dew plant and bladderwort etc. Insectivorous plants can be called partial heterotrophs.
NUTRITION IN PLANTS (CH-1) BOOK QUESTIONS (Private Book)
Study questions 1. Multiple choice questions I. i) Which one is an insectivorous plant? a) Lichen b) Venus fly-trap c) Mushrooms d) Yeast
ii) Two different organisms living together and both benefiting from each other, are known as a) Saprophytic b) Symbiotic c) Parasitic d) Heterotrophic
iii) The process, by which green plants prepare their own food is known as a) Photosynthesis b) Respiration c) Symbiosis d) None of these
iv) The green colour pigment in the leaves is a) Chlorophyll b) Anthocyanin c) Protoplast d) Chloropast
v) Tiny pores on the surface of leaves are a) Lamina b) Stomata c) Chlorophyll d) Leaf stalk
II. Fill in the blanks i) The process of taking or consuming and utilizing food is called nutrition. ii) Heterotrophs derive their food from other organisms iii) Lichen is the mutual combination of alga and fungus. iv) Dodder is an example of total parasite. v) Nitrogen requirement of insectivorous plants is provided by insects. vi) Saprophytic plants lack chlorophyll. vii) Green plants use Carbon dioxide and water to prepare food. viii) During photosynthesis, the gas released is oxygen ix) The presence of starch can be tested by using iodine solution. x) On testing with iodine, starch turns blue black in colour. xi) The green coloured pigment present in leaves is called chlorophyll
III. Give one word for the following : i) The pigment which gives green colour to leaves : Chlorophyll ii) Name a gas used in photosynthesis : Carbon dioxide iii) The pores present on the surface of leaves : Stomata
IV. Match the column Column A Column B i) Tiny pores in leaves Stomata ii) Needy by plants to make food Water, sunlight iii) A plant’s food factory Leaf iv) Live on other organisms and derive food from them Parasitic v) Two different organisms live together and both are beneficial Symbiosis vi) Plant feeding on insects Pitcher plant vii) Parasitic plant with yellow slender long tubular stem Amarbel
V.Define the following. 1. Define photosynthesis. Ans. Photo means ‘light’ and synthesis means ‘to combine’. Literally, photosynthesis means ‘synthesis in the presence of light’. It is a unique and the most important process by which plants synthesize their own food from simple inorganic substances like carbon dioxide (CO2) and water (H2O) in the presence of sunlight and chlorophyll. Carbon dioxide (CO2) is absorbed from the atmosphere through stomata present on the lower surface of the leaves and water is absorbed from the soil through the root system and transported to the leaves by xylems .The chlorophyll contained in the cells of the leaves traps the solar energy. Then photosynthesis takes place in the leaves. During photosynthesis because of the intracellular chemical reaction of carbon dioxide and water in the presence of sunlight and chlorophyll, carbohydrates are prepared and oxygen is released out. Hence, Oxygen is a photochemical by product of photosynthesis. The primary function of photosynthesis is to capture light energy, convert some of this light energy into chemical energy, and store this chemical energy in molecules of carbohydrates which are ultimately get converted into starch. The chemical equation of Photosynthesis is as under.
Sunlight CO2 + H2O ----------------------→ C6 H12 O6 + O2 ↑ Carbon dioxide Water Chlorophyll Carbohydrates Oxygen (Glucose) Note: Carbohydrates are the compounds made up of cabon, hydrogen and oxygen. Glucose (C6 H12 O6), Sugar (C12 H22 O11) and Starch (C6 H10 O5) .2.Mention the role of chlorophyll in photosynthesis. Ans. Chlorophyll is the green coloured pigment contained inside the chloroplasts of the cells of the leaves. It is the chief pigment involved in photosynthesis. For photosynthesis, the solar energy is trapped by the chlorophyll. Photosynthesis in the leaves is not possible in the absence of chlorophyll. Hence, chlorophyll plays a significant role in the process of photosynthesis.
3. From where does carbon dioxide enter a plant? Ans. Carbon dioxide (CO2) which is required for photosynthesis is absorbed from the atmosphere through small pores called stomata generally present on the lower surface of the leaves.
4. Which are the raw materials required for photosynthesis? Ans. Four things necessary for photosynthesis are:
1. Carbon dioxide (CO2):- The percentage of carbon dioxide in the atmosphere is 0.03. Carbon dioxide (CO2) which is required for photosynthesis is absorbed from the atmosphere through small pores called stomata generally present on the lower surface of the leaves.
2. Water: (H2O) :- Water is absorbed from the soil through the root system and transported to the leaves by xylems. 3.Chlorophyll: Chlorophyll is the green coloured pigment contained inside the chloroplasts of the cells of the leaves. It is the chief pigment involved in photosynthesis. For photosynthesis, the solar energy is trapped by the chlorophyll. Photosynthesis in the leaves is not possible in the absence of chlorophyll. Hence, chlorophyll plays a significant role in the process of photosynthesis
4. Light: Sun is the ultimate source of energy for all living organism. During photosynthesis Chlorophyll traps light energy from sunlight and some of this light energy is converted in to chemical energy and stored in the molecules of carbohydrates.
5. In which part of a plant is food made? Ans. In most plants chlorophylls are present inside the chloroplast in the cells of the leaves. So, photosynthesis takes place in the leaves, because of which leaves are called as the food factories of plants. But, in certain xerophytes like cacti, the leaves are modified into spines to minimize the loss of water by transpiration and the stem is thick, spongy and green. In such plants photosynthesis takes place in green stems instead of leaves.
6. What is produced during photosynthesis? Ans. During photosynthesis carbohydrates are formed in the form of Glucose (C6 H12 O6) and stored in the plant as starch (C6 H12 O6) and Oxygen is a photochemical by product of photosynthesis..
7. Name two insect-eating plants. Ans. The plants which feed on small insects to meet their nitrogen requirement are called insectivorous plants. The example of insectivorous plants are pitcher plants, venus fly-trap and sun dew plant and bladderwort ect. These are partially heterotrophs.