Living World
Cells, Tissues, Plant Nutrition, Transport and Reproduction in Plants
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Overview
The Living World forms a foundational unit in UPTET Paper II Science, bridging biology concepts from Classes 6–8. Questions typically test understanding of cell structure, tissue types, how plants make and transport food, and their reproductive mechanisms. This topic carries significant weight because it connects multiple NCERT chapters and appears consistently in TET examinations.
Students must master the cell as the basic unit of life, distinguish between plant and animal cells, understand tissue organisation, and grasp the complete picture of how plants survive — from photosynthesis to reproduction. The examiner often tests conceptual clarity through diagram-based questions, function-matching items, and application problems linking structure to function.
Success requires memorising key terms and processes while understanding *why* structures are designed the way they are. Rote learning alone fails when questions ask you to compare, contrast, or apply concepts to new situations.
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Key Concepts
• **Cell Theory**: All living organisms are made of cells; the cell is the structural and functional unit of life; all cells arise from pre-existing cells (Schleiden, Schwann, Virchow).
• **Prokaryotic vs Eukaryotic Cells**: Prokaryotes (bacteria) lack a membrane-bound nucleus; eukaryotes (plants, animals, fungi) have a true nucleus and membrane-bound organelles.
• **Plant Cell vs Animal Cell**: Plant cells have a cell wall, large central vacuole, and plastids (including chloroplasts); animal cells lack these but have centrioles.
• **Tissue Definition**: A group of similar cells performing a specific function. Plants have meristematic (dividing) and permanent (non-dividing) tissues.
• **Photosynthesis Equation**: Carbon dioxide + Water → (sunlight, chlorophyll) → Glucose + Oxygen. This is how plants make their own food (autotrophs).
• **Transport in Plants**: Water and minerals move upward through xylem (transpiration pull); food moves from leaves to other parts through phloem (translocation).
• **Modes of Reproduction**: Asexual (vegetative propagation, budding, fragmentation, spore formation) and sexual (involving flowers, pollination, fertilisation, seed formation).
• **Flower as Reproductive Organ**: Contains male part (stamen = anther + filament) and female part (pistil = stigma + style + ovary).
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Formulas / Key Facts
| Concept | Key Fact | |---------|----------| | **Cell discovery** | Robert Hooke (1665) observed cork cells; termed "cell" | | **Photosynthesis site** | Chloroplast (specifically grana and stroma) | | **Photosynthesis equation** | 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ | | **Xylem function** | Transports water and minerals upward (unidirectional) | | **Phloem function** | Transports food bidirectionally (translocation) | | **Stomata** | Tiny pores on leaves for gas exchange and transpiration | | **Meristematic tissue location** | Root tips, shoot tips, cambium | | **Permanent tissues** | Simple (parenchyma, collenchyma, sclerenchyma) and Complex (xylem, phloem) | | **Pollination types** | Self-pollination (same flower) and Cross-pollination (different flowers) | | **Agents of pollination** | Wind, water, insects, birds, animals | | **Double fertilisation** | Unique to angiosperms — one sperm fuses with egg (zygote), another with polar nuclei (endosperm) |