Class 12 Biology Notes for Punjab Board (2026-2027)
Chapter-wise solved notes for HSSC Part 2 Biology covering all 13 chapters from Thermoregulation & Osmoregulation to Ecology – including solved exercises, MCQs, short questions, and long questions aligned with the PCTB / PECTAA syllabus.
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Overview
Class 12 Biology under Punjab Board covers a carefully structured set of 13 chapters that build directly on the foundational concepts introduced in Class 11. The PCTB / PECTAA syllabus for HSSC Part 2 Biology takes students deeper into human body systems, molecular biology, genetics, and the applied sciences – areas that have significant relevance for students planning to pursue medicine, biosciences, or related fields after Intermediate.
The course begins with homeostasis-related topics: Thermoregulation and Osmoregulation (Chapter 13), followed by the Human Urinary System (Chapter 14). Students then study the Human Nervous System (Chapter 15) in considerable detail – covering neurons, nerve impulse propagation, the organization of the brain and spinal cord, and the effects of drugs on nervous coordination. The Human Endocrine System (Chapter 16) and Human Reproductive System (Chapter 17) round out the human physiology section.
From Chapter 18 onward, the focus shifts to genetics and molecular biology. Inheritance (Chapter 18) covers Mendelian genetics, blood group systems, sex determination, and sex linkage. Chromosome and DNA (Chapter 19) goes into DNA replication, gene expression, transcription, translation, and mutations. Biotechnology (Chapter 20) explores recombinant DNA technology and PCR, while Immunity (Chapter 21) examines the body's three lines of defence. The final chapters address Biostatistics (Chapter 22), Pharmacology (Chapter 23), Evolution (Chapter 24), and Ecology (Chapter 25) – providing a broad scientific context for biology's role in society and the environment.
These notes are designed for HSSC Part 2 students studying under any Punjab Board-affiliated examination body, including Lahore Board, Rawalpindi Board, Gujranwala Board, Faisalabad Board, Multan Board, Bahawalpur Board, Sahiwal Board, Sargodha Board, and D.G. Khan Board. All content follows the SLO-based curriculum issued by Punjab Curriculum and Textbook Board (PECTAA) for 2026-2027. Each chapter is available individually with solved exercises, MCQs, short questions, and long questions – suitable for chapter-wise revision and full exam preparation.