WHAT IS BIOLOGY

1.1 The Study of Life

Key Concept

  • Biology is the study of all forms of life.

The Biosphere

  • Biosphere: Encompasses all living things and their environments.

    • Diversity: Earth hosts an incredible variety of life.

    • All parts of the biosphere are interconnected.

  • Environments within the biosphere include:

    • Land Environments:

      • Biomes such as Tropical Rainforest, Grassland, Desert, Temperate Forest, Taiga, and Tundra.

    • Non-Biome Areas: Mountain zones, Polar Ice.

    • Water Environments:

      • Saltwater (oceans) and freshwater (lakes, rivers) ecosystems, including tidepools and estuaries.

Biodiversity

  • Biodiversity: Refers to the variety of life.

    • Increases from the poles to the equator.

    • Greater in consistently warm temperatures.

  • Approximately 2 million living species have been identified.

Characteristics of Organisms

  • All organisms share basic characteristics:

    • Composed of one or more cells.

    • Require energy for metabolism.

    • Respond to their environment.

    • Possess DNA that is passed to offspring.

Systems in Biology

  • Systems: Organized groups of interacting parts that define levels of life.

    • Examples include cells, body systems, and ecosystems.

    • Structure and function within biology are correlated.

Homeostasis

  • Homeostasis: Maintenance of constant internal conditions vital for survival.

    • Usually maintained through negative feedback, returning conditions to their normal point.

  • Example: Thermoregulation for body temperature control.

Evolution

  • Evolution: Explains both the unity and variation of life.

    • Involves changes in the genetic makeup of species over time.

    • Natural selection drives adaptations in organisms.

Nature of Science

  • Scientific Process: Biology relies on systematic inquiry involving observation, data recording, hypothesis formation, testing, and analysis.

    • Experiments help establish causality by manipulating independent and observing dependent variables.

Theories in Science

Definition of Science and Biology

  • Science: Systematic enterprise that builds and organizes knowledge through testable explanations and predictions.

  • Biology: Derived from Greek words meaning "life" and "study"; covers all aspects of living organisms and processes.

  • A theory explains a broad range of observations and is supported by substantial scientific evidence.

    • E.g., theories can evolve as new evidence emerges, such as bacteria causing ulcers.

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Branches of Biology

  • Pure Branches:

    • Morphology, Anatomy, Histology, Genetics, Ecology, etc.

  • Applied Branches:

    • Applied Botany: Agriculture, Horticulture.

    • Applied Zoology: Animal husbandry, Sericulture.

Specialized Fields in Biology

  • Botany: Study of plants including types like algae and flowering plants (Theophrastus: "Father of Botany").

  • Microbiology: Study of microscopic organisms known as microbes (Antonie van Leeuwenhoek: "Father of Microbiology").

  • Other fields include zoology, ecology, and various medical sciences (e.g., gynecology, pathology).

Characteristics of Life

  • Living organisms display specific characteristics: growth, reproduction, movement, nutrition, respiration, and homeostasis.

  • Understanding life requires recognizing these unique attributes.

Summary of Major Themes

  • Biology investigates both the unity and diversity in life.

  • Emphasis on systems, structure-function relationships, and homeostasis highlights the complexity of life forms.

  • Evolves with ongoing scientific inquiry, adapting with new discoveries in various biological subfields.