Title 1. PLANT AND ANIMAL BIOLOGY.pdf ✅

INTRODUCTION TO LIFE What is Biology? Biology is the scientific study of life. It's an incredibly vast and diverse field that seeks to understand everything about living organisms, from their smallest molecular components to their interactions with the global environment. Etymology of "Biology" The word "biology" has fascinating Greek roots: • "Bios" (βίος): Meaning "life" or "way of living." • "Logos" (λόγος): Meaning "study," "discourse," or "reason." The term "biology" in its modern scientific sense was independently coined around 1802 by German naturalist Gottfried Reinhold Treviranus and French naturalist Jean-Baptiste Lamarck. Characteristics of Life 1. Order (Organization): Living things exhibit a highly ordered and complex structure, from molecules to organisms. 2. Regulation (Homeostasis): Organisms maintain a stable internal environment despite external fluctuations. This self-regulation is called homeostasis. 3. Growth and Development: Organisms grow by increasing in size/number of cells and develop through controlled processes based on genetic instructions. 4. Energy Processing (Metabolism): Living things acquire and transform energy from their environment to power activities. Metabolism is the sum of all chemical reactions sustaining life. 5. Response to the Environment (Stimuli): Organisms detect and respond to changes in their surroundings. 6. Reproduction: Organisms produce new individuals of their own kind, ensuring species continuation (asexual or sexual). 7. Evolutionary Adaptation (Evolution): Populations of organisms change over generations in response to their environment, leading to adaptations that enhance survival and reproduction. Levels of Biological Organization Life is organized in a hierarchical manner, with each level building upon the one below it. • Atoms: Smallest units of matter (e.g., Carbon, Oxygen). • Molecules: Two or more atoms bonded together (e.g., water, DNA). • Organelles: Specialized structures within cells (e.g., mitochondria). • Cells: The fundamental unit of life. • Tissues: Groups of similar cells with a specific function. • Organs: Structures composed of different tissues for a specific function. • Organ Systems: Groups of organs cooperating for a major function. • Organism: An individual living being. • Species: Group of interbreeding organisms producing fertile offspring. • Population: Individuals of a single species in a specific area. • Community: All different populations of species interacting in an area.