| Type | Sub-type | Function | Location | | :--- | :--- | :--- | :--- | | Meristematic | Apical, Lateral, Intercalary | Cell division (growth) | Root tip, shoot tip, nodes | | Permanent | Simple (Parenchyma, Collenchyma, Sclerenchyma) | Storage, support, strength | Throughout plant body | | Permanent | Complex (Xylem & Phloem) | Transport | Stems, roots, veins |
1. Mitochondria (The Powerhouse)
2. Plastids (Found only in Plant Cells)
3. Endoplasmic Reticulum (ER)
4. Golgi Body (Golgi Apparatus)
5. Ribosomes
6. Centrosome
7. Vacuole
The cell is the structural and functional fundamental unit of life. Every living organism, from a single-celled amoeba to a complex human, is composed of cells. This chapter bridges the gap between the molecular level and the organism level.
Key Concepts:
| Organelle | Found in | Function | | :--- | :--- | :--- | | Nucleus | Both | Controls all cell activities; contains DNA & Chromosomes. | | Mitochondria | Both | Powerhouse of cell; produces ATP energy. | | Ribosome | Both | Protein synthesis. | | ER (Endoplasmic Reticulum) | Both | Transport of materials. (Rough ER = protein; Smooth ER = lipid) | | Golgi Body | Both | Packaging & secretion of cell products. | | Lysosome | Animal | Suicidal bag; digests waste & germs. | | Chloroplast | Plant | Photosynthesis (contains green pigment Chlorophyll). | | Cell Membrane | Both | Semi-permeable; controls entry/exit of substances. |
✅ Tip: In exams, draw a simple labeled diagram of a plant cell or animal cell – it carries marks even if explanation is short.
| Tissue Type | Function | Location | | :--- | :--- | :--- | | Epithelial | Protection, secretion | Skin, lining of organs | | Connective | Support, bind | Blood, bone, cartilage, tendon | | Muscular | Movement | Skeletal, smooth, cardiac | | Nervous | Impulse transmission | Brain, spinal cord, nerves | ssc biology chapter 2 hand note exclusive
Growth and reproduction require cells to divide. There are three types: