Theme 5 of ch-1

• Major themes of biology


  • Organization
  • Information
  • Energy and matter
  • Interactions
  • Evolution
• Themes of biology


  • They help understand life as a whole
  • Life on Earth is diverse, resilient, powerful, intelligent, and mystifying
  • Understanding of the five major themes has been able to be categorized over time
• Biological organization


  The hierarchy of life on Earth: biosphere, ecosystem, community, population, organism, organ system, organ, tissue, cell, organelle, molecule and atom
• Biological organization


  • New properties emerge at each successive level due to interactions among components at the lower levels
• Structure and function of biological components

  Are interrelated
• Structure-function relationship


  • The hummingbird's anatomy allows its wings to rotate at the shoulder, enabling it to fly backward or hover in place
  • The hummingbird's long, slender beak allows it to feed on nectar while hovering
• Cell


  Basic unit structure and function of an organism, the lowest level of organization that can perform all activities required for life
• Cells


  • Prokaryote
  • Eukaryote
• Eukaryotic cells


  Contain membrane-enclosed organelles, including DNA in nucleus
• Prokaryotic cells


  Lack membrane-enclosed organelles
• Prokaryotic cell


  • DNA (no nucleus)
  • Membrane
  • Environment
• Eukaryotic and prokaryotic cells differ in size and complexity
• DNA


  Genetic material that contains the instructions for the expression of genes
• Energy flow and chemical cycling

  1. Chemicals from the soil and air

  2. Fungi and bacteria break down leaf litter and dead organisms

  3. Returning chemicals to the soil
• Organisms


  • Interact continuously with physical factors
  • Plants take up nutrients from the soil and chemicals from the air and use energy from the sun
  • Interactions among plants, animals, and other organisms affect the participants in varying ways
• Feedback regulation


  • A process is regulated by its output or product
  • In negative feedback, accumulation of the product slows its production
  • In positive feedback, a product speeds up its own production
  • Feedback is a type of regulation common to life at all levels, from molecules to ecosystems
• Evolution


  • The process of change that has transformed life on Earth, accounts for the unity and diversity of life
  • It also explains evolutionary adaptation and the match of organisms to their environment
• Domains of life


  • Bacteria
  • Archaea
  • Eukarya (protists, fungi, plants, animals)
• Bacteria and Archaea consist of prokaryotes
• Domain Eukarya includes various groups of protists as well as fungi, plants, and animals