Biology (PGT) — HTET Level 3 Study Notes

Overview

Biology at the PGT level for HTET covers the entire Class XI–XII NCERT syllabus across Botany, Zoology, Genetics, and Biotechnology. This is a content-heavy subject where factual accuracy and conceptual clarity determine scores. Expect questions on plant and animal physiology, cell biology, ecology, human reproduction, genetics problems, and applications of biotechnology.

The PGT paper tests your depth of knowledge — not just definitions but mechanisms, processes, and their significance. Questions often involve diagrams (though you must visualize them mentally), numerical genetics problems, and application-based scenarios. Mastering the NCERT textbooks thoroughly is non-negotiable; most questions are directly or indirectly sourced from these texts.

Prioritize high-yield areas: Genetics and Evolution, Human Physiology, Plant Physiology, and Biotechnology. These sections consistently carry more weight and offer scoring opportunities if concepts are clear.

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Key Concepts

• **Cell as the structural and functional unit**: Prokaryotic vs eukaryotic cells, cell organelles and their functions, cell cycle phases (G1, S, G2, M), and differences between mitosis and meiosis.

• **Biomolecules**: Structure and function of carbohydrates, proteins, lipids, nucleic acids; enzyme action follows lock-and-key or induced-fit model; Michaelis-Menten kinetics concept.

• **Plant Physiology essentials**: Photosynthesis (light and dark reactions, C3 vs C4 vs CAM pathways), respiration (glycolysis, Krebs cycle, ETC), transpiration pull theory, mineral nutrition and nitrogen cycle.

• **Human Physiology systems**: Digestive (enzymatic action), respiratory (oxygen-haemoglobin dissociation curve), circulatory (cardiac cycle, double circulation), excretory (nephron function, counter-current mechanism), nervous (synapse, reflex arc) and endocrine (hormones and feedback).

• **Genetics foundations**: Mendelian inheritance, deviations from Mendelism (incomplete dominance, codominance, multiple alleles, polygenic inheritance), linkage and crossing over, sex determination (XX-XY, ZW-ZZ), chromosomal disorders.

• **Molecular Biology**: DNA structure (Watson-Crick model), replication (semi-conservative), transcription, genetic code properties, translation, lac operon regulation.

• **Biotechnology applications**: Recombinant DNA technology, PCR, gel electrophoresis, transgenic organisms, gene therapy, Bt crops, golden rice, DNA fingerprinting.

• **Ecology and Environment**: Ecosystem components, food chains and webs, ecological pyramids, biogeochemical cycles, ecological succession, biodiversity and conservation strategies.