Introduction to Biology

Introduction to Biology

• Biology is the scientific study of life and living organisms.
• It encompasses various disciplines, including botany (plant life), zoology (animal life), microbiology (microscopic organisms), and more.
• Biology seeks to understand the structure, function, growth, evolution, distribution, and taxonomy of living things.
• Key aspects involve mechanisms of inheritance, diversity, and interactions within ecosystems.

Branches of Biology

• Botany: Focuses on the study of plants including their structure, function, growth, reproduction, and evolution.
• Zoology: Studies animals, covering their behaviour, physiology, anatomy, classification, and evolution.
• Microbiology: Investigates microscopic organisms like bacteria, viruses, fungi, and protists. It explores their structure, function, genetics, and role in ecosystems.
• Ecology: Studies the relationships between organisms and their environment and explores the interactions within and among populations and communities.
• Genetics: Explores heredity and the variation of inherited characteristics.
• Molecular Biology: Investigates the biological processes occurring at the molecular level, such as DNA replication, protein synthesis, and gene expression.
• Physiology: Examines the functions of the various organ systems in organisms.
• Evolutionary Biology: Studies the processes that have led to the diversity of life on Earth, including natural selection, adaptation, and speciation.
• Cell Biology: Investigates the structure, function, and behaviour of cells, which are the basic units of life.

Fundamental Concepts

• Cells: The basic unit of life, with various structures and functions.
• Energy Flow: Explains the movement of energy through the ecosystem with the key concept of photosynthesis and respiration.
• Homeostasis: The ability of a living organism to maintain a stable internal environment.
• Reproduction: The process by which organisms produce offspring, essential for the continuation of species.
• Adaptation: The process where organisms adjust to different environmental conditions over time.
• Evolution: The process of change in organisms over time, driven by natural selection.
• Organization: Living organisms exhibit increasingly complex organization, ranging from molecules to cells to tissues to organ systems.
• Diversity: A vast number of species exist with different characteristics and adaptations.
• Interdependence: Organisms interact, and sometimes rely on each other, in complex food chains and networks.
• Natural Selection: A key mechanism driving evolution where organisms better adapted to their environment are more likely to survive and reproduce.

Key Biological Processes

• Photosynthesis: The process by which plants and certain other organisms use sunlight to synthesize foods from carbon dioxide and water.
• Cellular Respiration: The process in which cells break down food molecules to release energy.
• Meiosis: A type of cell division that produces gametes (sex cells), each with half the number of chromosomes as the parent cell.
• Mitosis: A type of cell division that results in two identical daughter cells from one parent cell.
• Protein Synthesis: The process where cells build proteins from amino acids under the direction of DNA.
• DNA Replication: The process by which DNA makes a copy of itself before cell division.
• Gene Expression: The process by which information from a gene is used in the synthesis of a functional gene product.

Classification of Living Organisms

• Taxonomy: The science of classifying and naming organisms in an organized hierarchy. Key levels are domain, kingdom, phylum, class, order, family, genus, and species.
• Binomial Nomenclature: Organisms are given two names – the genus and species.
• Phylogenetic Trees: Diagrams used to illustrate evolutionary relationships among different groups of organisms.