Characteristics of Life

• Characteristics of life

  • Living things are made up of cells
  • Living things reproduce
  • Living things are based on a universal genetic code (DNA)
  • Living things grow and develop
  • Living things obtain and use materials and energy
  • Living things respond to their environment
  • Living things maintain a stable internal environment (homeostasis)
  • Taken as a group, living things change over time
• Biological organization (smallest to largest)

  1. Subatomic particle
  2. Atom
  3. Molecule
  4. Organelle
  5. Cell
  6. Tissue
  7. Organ
  8. Organ System
  9. Organism
• Why are viruses not classified as living?

  • Don't grow
  • Don't need food to fuel metabolic activity
  • Cannot use genetic material by themselves