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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...
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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...
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The Fundamental Unit of Life class 9 Notes

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  The Fundamental Unit of Life class 9 Notes Introduction All living organisms like plants, animals, and human beings are made up of tiny microscopic structures called cells . The cell is the basic structural and functional unit of life . This means: It forms the structure of all living bodies. It performs all the functions necessary for life such as respiration, nutrition, and reproduction. Discovery of Cell The cell was first discovered by Robert Hooke in 1665 while observing a thin slice of cork under a microscope. Later, Anton van Leeuwenhoek observed living cells in pond water. Cell Theory The cell theory was proposed by: Matthias Schleiden Theodor Schwann According to the Cell Theory:      1) All living organisms are made up of cells.      2) The cell is the basic unit of life.      3) All cells arise from pre-existing cells. Why Are Cells Important? Every plant, animal, and human body is made up of cells. Cells carry out ...
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