Life processes - part 1 ( nutrition in plants and animals)

These slides contain part 1 of chapter 1 of biology.

1. LIFE PROCESSES PART- 1 FROM: RITIMA MANHAS YOU TUBE: SHORT SHOT BIOLOGY SLIDE SHARE: Missritimabiologyexp

2. TOPICS TO BE STUDIED IN THIS CHAPTER NUTRITION TRANSPORTATION METABOLISM RESPIRATION REPRODUCTION EXCRETION DIFFERENCE BETWEEN PLANT AND ANIMAL LIFE PROCESSES

3. WHAT IS LIFE PROCESS? Life processes are the activities that living organisms perform to survive, grow, and develop.  Examples of life processes: Nutrition: The process of obtaining energy and nutrients from food Respiration: The process of releasing energy by breaking down glucose Transportation: The process of distributing food and oxygen throughout the body Excretion: The process of removing waste and toxic substances from the body Growth: The process of increasing in size and developing new features Reproduction: The process of creating new organisms Response to stimuli: The process of reacting to changes in the environment

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5. NUTRITION Nutrition is the process of how organisms take in food and use it for energy and growth. It also refers to the way organisms use nutrients from food.

6. NUTRION IN ANIMALS Animals derive their nutrition either by eating plants directly (herbivores), or indirectly by eating animals which have consumed plants (carnivores). Some animals feed on both plants and animals; these animals are termed omnivores. All organisms require food for their survival and growth. Food has different components, called nutrients, like carbohydrates, fats, minerals, proteins, and vitamins, which are required for the maintenance of the body. These components are complex and cannot be used directly, so they are broken down into simpler components by the process of digestion.

7. PROCESS OF NUTRITION IN ANIMALS Ingestion Ingestion is the process of taking in food. Digestion In this process, the larger food particles are broken down into smaller, water-soluble particles. There are physical or chemical processes for digesting food. Absorption The digested food is absorbed into the bloodstream through the intestinal wall. Assimilation The absorbed food is used for energy, growth and repair of the cells of the body. Egestion The undigested food is removed from the body in the form of faeces . This process is known as egestion.

8. NUTRITION IN AMOEBA Amoeba get nutrients through a process called phagocytosis , which is a type of holozoic nutrition. In this process, the entire organism engulfs food. Steps of holozoic nutrition in amoeba Ingestion : Amoeba forms pseudopodia to engulf food particles. Digestion: The food is captured in a food vacuole that acts as a temporary stomach. Digestive juices are secreted into the food vacuole. Assimilation : The digested food is absorbed into the cytoplasm and used for growth, repair, and energy production. Egestion: Undigested food is eliminated from any part of the body's surface.

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10. NUTRITION IN PLANTS All green plants exhibit autotrophic nutrition as they synthesize their food by the process of photosynthesis, using light, carbon dioxide and water. Plants are autographs, they have an autotrophic mode of nutrition. They perform photosynthesis to prepare their own food.

11. PHOTOSYNTHESIS Photosynthesis, the process by which green plants and certain other organisms transform light energy into chemical energy. The mode of nutrition in which an organism prepares its own food is called autotrophic nutrition. Green plants and blue-green algae follow the autotrophic mode of nutrition. The organisms which carry out autotrophic nutrition are called autotrophs (green plants). Autotrophic nutrition is fulfilled by the process, by which autotrophs intake CO2 and H2O, and convert these into carbohydrates in the presence of chlorophyll, sunlight is called photosynthesis

12. . SITE OF PHOTOSYNTHESIS : CHLORAPLAST

13. RAW MATERIALS FOR PHOTOSYNTHESIS: Sunlight Chlorophyll: Sunlight absorbed by chloroplast CO2: Enters through stomata, and oxygen (O 2 ) is released as a byproduct through stomata on the leaf. Water: Water + dissolved minerals like nitrogen, phosphorous etc., are taken up by the roots from the soil.

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15. MAIN EVENTS OF PHOTOSYNTHESIS: Absorption of light energy by chlorophyll. Conversion of light energy into chemical energy + splitting (breaking) of water into hydrogen and oxygen. Reduction of CO2 to carbohydrates. Sunlight activates chlorophyll, which leads to splitting of the water molecule. The hydrogen, released by the splitting of a water molecule is utilized for the reduction of carbon dioxide to produce carbohydrates. Oxygen is the by-product of photosynthesis. Carbohydrate is subsequently converted into starch and is stored in leaves and other storage parts. The splitting of water molecules is a part of the light reaction.

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17. STOMATA Stomata are tiny pores in plant leaves that are made up of guard cells and subsidiary cells. They are surrounded by a tough, flexible cell wall. Structure of stomata Guard cells: A pair of specialized cells that control the opening and closing of the stoma. The shape of the guard cells changes based on the amount of water and potassium in the cells. Subsidiary cells: Accessory cells that surround the guard cells. They protect the epidermal cells when the guard cells expand. Cell wall: A tough, flexible cell wall that surrounds the pore. Function of stomata Stomata regulate the rate of gas exchange between the inside of the leaf and the outside atmosphere. They play an important role in photosynthesis. They regulate the rate of transpiration. They help in the exchange of carbon dioxide and oxygen.

18. STRUCTURE OF STOMATA

19. OPENING AND CLOSING OF STOMATA The opening and closing of stomatal pores is regulated by guard cells by increasing or decreasing the amount of water in them. When water enters the guard cells, they become turgid. This results in opening of stomata) pore. When water exits from the guard cells, they become flaccid

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