Chapter 2 Biodiversity Notes - Class 9 Biology Punjab Board

This page provides Class 9 Biology Chapter 2, Biodiversity, notes for Punjab Board students following the PCTB syllabus for the 2026-2027 session. It includes solved exercises, important MCQs, and short and long questions, and can be read online chapter by chapter by SSC Part 1 and Matric Part 1 students.

Chapter 2 of Class 9 Biology, Biodiversity, explains why living organisms are grouped into categories and how this classification helps scientists study and organize the huge variety of life on Earth. The chapter covers taxonomic ranks from kingdom down to species, and traces how classification systems have developed historically, from early two-kingdom systems to the modern domain-based approach.

Students go through the three domains of living organisms and look more closely at the classification of domain Eukarya, which includes protists, fungi, plants and animals. The chapter also addresses where viruses fit within classification, since they do not comfortably belong to any of the standard biological categories, and closes with binomial nomenclature, the two-name system used to scientifically name species.

This chapter is important for Punjab Board exams because it introduces terminology and ranking systems used repeatedly in later Biology chapters, and questions on taxonomic ranks and binomial nomenclature are common in board papers. These solved notes are structured to make classification concepts and their exceptions, like viruses, easier to recall during revision and exam preparation.