Botany — Last-Minute Revision
High-priority revision for the TS Inter 2nd Year Botany board exam — high-yield units, must-know diagrams, and exam-day strategy. Paper: 60 marks · 3 hours.
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High-Yield Units
- •Genetics — Mendel's laws, dihybrid cross, linkage, mutations (LAQ+SAQ)
- •Molecular Biology — DNA replication, transcription, translation (LAQ)
- •Biotechnology — recombinant DNA, PCR, gene cloning, Bt crops (LAQ+SAQ)
- •Plant Physiology — photosynthesis (C3/C4/CAM), respiration, transpiration (LAQ)
- •Microbiology — bacteria, viruses, mycology applications (SAQ)
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Diagrams Must-Know
- •Chloroplast ultrastructure — grana, stroma, thylakoid membrane
- •Mitosis and Meiosis stages (prophase, metaphase, anaphase, telophase)
- •Calvin cycle (C3 pathway) — RuBP, 3-PGA, G3P steps
- •DNA double helix structure with base pairing
- •Lac operon — inducer/repressor mechanism diagram
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Key Concepts to Re-read
- •Law of Segregation vs. Law of Independent Assortment — give examples
- •Difference between DNA replication and transcription
- •Restriction enzymes — palindromic sites, sticky ends, blunt ends
- •Eutrophication and biological magnification — definition + stages
- •Polymerase Chain Reaction (PCR) — 3 steps: denaturation, annealing, extension
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Common Mistakes
- •Don't confuse genotype and phenotype ratios in dihybrid crosses
- •C4 plants: mesophyll → bundle sheath (not the reverse)
- •PCR uses DNA polymerase, not RNA polymerase
- •Transgenic and GMO are related but not synonymous — state definitions carefully
- •In lac operon, absence of glucose activates; absence of lactose also affects
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Exam-Day Tips
- •Label all diagrams fully — parts without labels lose marks
- •For genetic crosses, draw Punnett square clearly, state the ratio
- •Define terms before answering — one mark is often for the definition alone
- •For molecular biology, write the enzyme name with each step
- •Read 'explain', 'describe', 'compare' carefully — they ask for different things