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Why do we fall Ill? class 9 Notes

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Why do we fall Ill? class 9 Notes Introduction Health means physical, mental, and social well-being, while disease means disturbance in normal body functions. We fall ill due to infection by microorganisms, poor nutrition, or unhealthy surroundings . Understanding diseases helps us prevent them through hygiene, vaccination, and a healthy lifestyle . Health and its Failure The significance of "HEALTH" Health is very important for individuals as well as for society.  Good health helps a person live a happy, active, and productive life.  The significance of health can be understood in the following points: 1. Efficient Working A healthy person can perform daily activities and work efficiently without feeling tired or weak. 2. Proper Growth and Development Good health is necessary for the physical and mental development of children and adults. 3. Better Quality of Life Healthy people can enjoy life, participate in social activities, and live with happiness and satisfaction...

Diversity in Living Organisms class 9 Notes

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 Diversity in Living Organisms class 9 Notes Introduction The Earth is home to a huge variety of living organisms. From tiny microscopic bacteria to giant elephants and tall trees, life exists in many different forms. This variety of living forms is called biodiversity . The chapter “Diversity in Living Organisms” helps us understand how and why living organisms are different from each other and how scientists classify them into groups for easy study. The five-kingdom classification was proposed by Robert Whittaker in 1969, and Monera was placed as the first kingdom because it contains the most basic forms of life. What is Diversity? Diversity means variety . In biology, diversity refers to the wide range of different types of plants, animals, and microorganisms found on Earth. Examples: Plants like mango tree, cactus, and grass Animals like lion, fish, and butterfly Microorganisms like bacteria and fungi Why Do We Classify Living Organisms? Because there are millions of spe...

Tissues class 9 Notes

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  Tissues class 9 Notes Introduction A tissue is a group of similar cells that work together to perform a specific function. In multicellular organisms, cells are organized in the following way:                        Cells → Tissues → Organs → Organ System → Organism Why Do We Need Tissues? In unicellular organisms, one cell performs all functions. But in multicellular organisms:                1) Different cells perform different functions                2) Division of labour increases efficiency                3) Body functions properly and systematically This concept is called division of labour . Are Plants and Animals Made of Same Types of Tissues? No, plants and animals are not made of the same types of tissues. Although both are multicellular and made of cells...