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1. Cells as the Basic Unit of Life Cell Theory • Cell Structure • Animal Cell Types

2. Cell Theory 1. All living things are made up of one or more cells. 2. The cell is the basic unit of structure and function of organisms. 3. All cells arise from pre-existing cells. Modern additions: - Cells contain hereditary information (DNA). - Energy flow (metabolism) occurs within cells.

3. Cell Structure Main Components: - Plasma Membrane: Controls movement of substances. - Cytoplasm: Jelly-like fluid with organelles. - Nucleus: Control center, stores DNA. - Organelles: Specialized structures with functions.

4. Organelles in Animal Cells - Mitochondria: Powerhouse, makes ATP. - Ribosomes: Protein synthesis. - Endoplasmic Reticulum (RER & SER): Proteins and lipids. - Golgi Apparatus: Packages and transports. - Lysosomes: Digestion and waste removal. - Cytoskeleton: Shape and movement. - Centrioles: Cell division.

5. Types of Animal Cells • Epithelial Cells – cover and protect surfaces. • Muscle Cells – specialized for movement. • Nerve Cells (Neurons) – transmit impulses. • Connective Tissue Cells – support and bind. • Reproductive Cells – sperm and egg.

6. Summary - Cell Theory: All organisms are made of cells; cells are the basic unit of life. - Structure: Plasma membrane, cytoplasm, nucleus, organelles. - Animal Cells: Epithelial, muscle, nerve, connective, reproductive.