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Chemistry LibreTexts

Unifying Themes in Biology

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  • biology-hi_572299b1b63df.png

    Unifying themes connect concepts from many fields of biology. 

    Systems - All levels of life have systems of related parts

    A system is an organized group of interacting parts. 

    • A cell is a system of chemicals a processes
    • A body system includes organs that interact
    • An ecosystem includes living and nonliving things that interact

    Structure and function -  are related in biology

    Structure determines function

    • Proteins with different structures have different functions
    • Intestinal muscle cells have a different structure and function than heart muscle cells
    • Different species have different structures with different functions

    Homeostasis - organisms must maintain homeostasis to survive in diverse environments

    Homeostasis is the maintenance of constant internal conditions

    • Homeostasis is usually maintained through negative feedback
    • Negative feedback systems return a condition to its normal point

    Evolution - explains the unity and diversity of life

    Evolution is the change in living things over time

    • The genetic makeup of a population of a species changes
    • Can occur through natural selection of adaptations
    • Adaptations are inherited traits that benefit a species that are passed to future generations

    Watch the video below for more insight into the four unifying themes of biology.