Chapter - 1, Nutrition in Plants, Science, Class 7

Chapter - 1, Nutrition in Plants, Science, Class 7

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  CHAPTER – 1 NUTRITIONIN PLANTS BY SHIVAM PARMAR (ENTREPRENEUR & TEACHER)
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  INTRODUCTION ◦ Living organismssuch as plants and animals survive on food. ◦ The food gives them the energy to perform several activities in their life and helps in the growth. 2
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  NUTRIENTS ◦ Nutrients -Certain substances are present in the foods that help in the survival of the organisms. These special substances are called nutrients for example, proteins, vitamins, carbohydrates, minerals and fats. ◦ Some living organisms like plants synthesize their food by themselves while others such as animals depend upon the plants and other animals for their food. 3
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  MODE OF NUTRITION INPLANTS Based on the mode of nutrition organisms can be divided into two categories: ◦ Autotrophic Organisms - They can prepare their food by themselves such as plants ◦ Heterotrophic Organisms - They depend upon other organisms for their food such as animals 4
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  CELLS IN LIVINGORGANISMS Cells are tiny units that help make up a living organism. Hence they are also called building blocks of an organism. A cell is constituted of three major parts : ◦ A thin outer layer called the cell membrane. ◦ A spherical structure located at the centre of the cell called a nucleus. ◦ A jelly-like substance that surrounds a nucleus called the cytoplasm. 5
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  SINGLE AND MULTI-CELLULAR ORGANISMS ◦Organisms that are made up of just one cell are called single-celled or Unicellular organisms. E.g. Amoeba ◦ Organisms with more than one cell in their body are called multicellular organisms. ◦ All human beings, plants and animals are multicellular organisms. 6
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  HOW DO PLANTS PREPARETHEIR FOOD? Plants prepare their food with the help of certain raw materials that they gather from their surroundings: ◦ water ◦ carbon dioxide ◦ sunlight ◦ minerals ◦ chlorophyll The process by which plants prepare their food by using these raw materials is called Photosynthesis. 7
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  PROCESS OF PHOTOSYNTHESIS ◦Carbon dioxide is taken in through tiny pores on the leaves called stomata. ◦ Water and minerals that are required for the process are transported to the leaves from the roots through the stem. ◦ Chlorophyll helps the leaves use the energy from the sunlight to prepare food using the carbon dioxide, water and minerals. ◦ Oxygen is released as a by-product from this process. 8
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  ULTIMATE SOURCE OFENERGY FOR ALL LIVING ORGANISMS? ◦ We know that the plants use solar energy to make their food. ◦ The herbivores animals depend upon the plants for their food. Animals (carnivores) that do not eat plants depend upon the herbivores animals. Therefore, all of the living organisms directly or indirectly receive their energy from the Sun. 9
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  HOW DO PLANTSGENERATE PROTEINS AND FATS? ◦ Along with carbohydrates, plants can also produce proteins and fats which are formed with the help of Nitrogen. ◦ Nitrogen is present in large amounts in the air but plants cannot consume the nitrogen directly from the atmosphere. ◦ The soil often contains some bacteria that are capable of converting the nitrogen into nitrates which can be the used by the plants. ◦ Also, fertilizers used by farmers and gardeners contain a high amount of Nitrogen which mixes into the soil and is used by the plants. 10
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  OTHER MODES OFNUTRITION ◦ Most of the plants have green pigment called chlorophyll and can make their own food. ◦ Some plants do not have chlorophyll and cannot synthesize their own food and are known as Heterotrophic plants ◦ This type of nutrition can be categorized into 1. Parasitic mode of nutrition 2. Insectivorous mode of nutrition 3. Saprophytic mode of nutrition 4. Symbiotic mode of nutrition 11
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  PARASITIC MODE OF NUTRITION ◦Some plants live on another plant for their nutrition., these are called Parasites. ◦ The plants on which these parasitic plants survive are called the host. ◦ For Example, Cuscuta is a parasitic plant. 12
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  INSECTIVOROUS MODE OF NUTRITION ◦These plants are green and carry out photosynthesis. ◦ But they grow in nitrogen-deficient soils. ◦ So, in order to get nitrogen, they feed on insects. ◦ These insectivorousplants have their parts modified for attracting and catching insects. ◦ For example - The pitcher plant, Venus flytrap etc. 13
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  SAPROPHYTIC MODE OF NUTRITION◦ Some organisms survive on decaying food and organisms. ◦ The organisms that survive because of the saprotrophic nutrition are called Saprophytes. ◦ The saprophytes secrete digestive juices on the decaying and dead matter. ◦ These juices convert the matter into a solution. ◦ The saprophytes that absorb the nutrients from the solution. ◦ For Example : Bread mould, Fungi (yeast and mushrooms) are a saprophytes that can be found on stale food and pickles which are exposed to the hot and humid environment. 14
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  SYMBIOTIC MODE OF NUTRITION ◦Sometimes organisms live together to share shelter and food with each other. These are said to have a symbiotic relationship. ◦ Example - Fungi live in the roots of the trees. These fungi take food from the trees and in return help the trees in absorbing water and nutrients from the soil. 15
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  REPLENISHING THE SOILWITH NUTRIENTS ◦ Plants get their nutrients from the soil mainly hence there is a need to replenish the soil again with nutrients so that the plants can survive on it. ◦ Fertilizers and manure are often used to replenish the soil with the nutrients. They contain potassium, phosphorus and nitrogen all of which are important for the plants. 16
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  ◦ A bacteriumcalled Rhizobium is present in the soil which can convert nitrogen present in it in the form that can be consumed by the plants. ◦ The Rhizobium generally lives in the roots of the plants such as peas, beans, grams and legumes and provides nitrogen to these plants. This is also an example of a symbiotic relationship. The farmers often do not need to use fertilizers while growing such crops. 17
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  THANK YOU 18