Cell_The_Fundamental_Unit_of_Life.pptxff

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1. Cell – The Fundamental Unit of Life Understanding the Structure and Functions of a Cell

2. Introduction to Cells - All living organisms are made up of cells. - The cell is the basic structural and functional unit of life. - Cells are like tiny building blocks that form tissues, organs, and ultimately, the entire body. Why is a Cell Important? - It carries out all life processes (growth, reproduction, respiration, etc.). - It contains genetic material (DNA/RNA) that passes traits from one generation to another.

3. Discovery of the Cell - Robert Hooke (1665): Discovered cells in cork using a microscope and coined the term 'cell.' - Anton van Leeuwenhoek (1674): Observed living cells in pond water. - Schleiden & Schwann (1838-39): Proposed the Cell Theory: 1. All living things are made of cells. 2. The cell is the basic unit of life. - Rudolf Virchow (1855): Added that all cells arise from pre-existing cells.

4. Types of Cells Based on Structure: 1. Prokaryotic Cells (e.g., Bacteria) - Simple, small in size - No nucleus (genetic material floats in cytoplasm) - No membrane-bound organelles 2. Eukaryotic Cells (e.g., Plants, Animals) - Complex, larger in size - Have a well-defined nucleus - Have membrane-bound organelles Based on Number of Cells: 1. Unicellular Organisms – Made up of a single cell (e.g., Amoeba, Bacteria). 2. Multicellular Organisms – Made up of many cells (e.g., Humans, Plants).

5. Structure of a Cell A typical eukaryotic cell consists of three main parts: 1. Cell Membrane (Plasma Membrane) - Outer covering of the cell. - Semi-permeable: Allows only selective substances to pass. 2. Cytoplasm - Jelly-like fluid inside the cell. - Contains all organelles (tiny structures with specific functions). 3. Nucleus - The control center of the cell. - Contains DNA, which carries genetic information.

6. Cell Organelles and Their Functions - Mitochondria: Powerhouse of the cell, produces energy. - Ribosomes: Protein synthesis. - Endoplasmic Reticulum: Transports materials (Smooth ER & Rough ER). - Golgi Apparatus: Packages and distributes proteins. - Lysosomes: Digest waste materials. - Vacuoles: Stores water and nutrients (larger in plant cells).

7. Difference Between Plant and Animal Cells - Plant Cells: - Have a cell wall. - Contain chloroplasts for photosynthesis. - Large central vacuole. - Animal Cells: - No cell wall. - No chloroplasts. - Small or no vacuoles.

8. Functions of Cells 1. Growth and Development – Cells multiply through division. 2. Reproduction – In unicellular organisms, a single cell divides to form new life. 3. Metabolism – Energy production and chemical reactions take place in cells. 4. Response to Stimuli – Cells react to environmental changes.

9. Importance of Cells in Daily Life - Medical Science: Understanding cells helps in disease treatment (e.g., cancer research). - Genetics: Study of cells helps in DNA modification (e.g., cloning, genetic engineering). - Agriculture: Cell studies help in improving crops and food production.

10. Conclusion - Cells are the basic unit of life, responsible for all functions in living organisms. - The study of cells helps us understand life, disease, and evolution. - With advancements in science, our knowledge of cells continues to grow, opening new possibilities in medicine and technology.

11. Thank You! Do you have any questions? Interesting Fact: The human body has around 37 trillion cells!