This textbook is designed for first-year college students in Pakistan. It introduces the fundamental principles of biology, from the structure of living organisms to their functions, classification, and diversity. The book develops both conceptual knowledge and practical skills, preparing students for medical, agricultural, and life sciences fields. Contents Summary 1. Introduction to Biology o Branches of biology (botany, zoology, microbiology, biotechnology). o Relationship of biology with other sciences. o Applications of biology in daily life. 2. Biological Molecules o Carbohydrates, proteins, lipids, nucleic acids. o Enzymes: nature, properties, mechanism of action, and factors affecting activity. 3. The Cell o Discovery of cell, cell theory. o Structure of prokaryotic & eukaryotic cells. o Cell organelles and their functions. o Cell division (mitosis & meiosis). 4. Variety of Life o Five-kingdom system of classification. o Characteristics of viruses, bacteria, algae, fungi, protozoa, and plants. o Diversity of animals (invertebrates to vertebrates). 5. Kingdom Prokaryotae (Monera) o Structure, reproduction, and importance of bacteria. o Harmful vs. useful bacteria. 6. Kingdom Protista o Protozoa, algae, slime molds. o Economic importance and life cycles. 7. Kingdom Fungi o Structure, nutrition, reproduction. o Role in medicine, food, and decay. 8. Kingdom Plantae o Structure of bryophytes, pteridophytes, gymnosperms, angiosperms. o Adaptations and importance. 9. Kingdom Animalia o Invertebrate and vertebrate phyla. o Major characteristics and significance of animals. 10. Bioenergetics o Photosynthesis (light & dark reactions). o Respiration: aerobic & anaerobic. o ATP and energy transfer. 11. Nutrition o Modes of nutrition in plants & animals. o Human digestive system and disorders. 12. Gaseous Exchange o Respiratory system in plants and animals. o Human breathing mechanism and gas exchange. 13. Transport o Transport in plants (xylem, phloem, transpiration). o Human circulatory system (heart, blood, blood vessels). 14. Excretion o Waste removal in plants & animals. o Human excretory system (kidneys, nephron, urine formation). 15. Coordination and Control o Nervous system and endocrine system in humans. o Coordination in plants (tropisms, hormones). Learning Outcomes By the end of Biology Intermediate Part 1, students should: • Understand the structure and function of living organisms. • Explain biological diversity and classification. • Apply concepts of cell biology, bioenergetics, and physiology. • Develop scientific skills through experiments and observation. • Appreciate the role of biology in human welfare and environmental balance.