all living organisms

all living organisms

1. are organized

   • composed from the cells 100 trillion cells in human body
     • cell is a smallest structural and functional unit of an organiosm
   • levels of organization
     • atom, molecule, cell, tissue, organ, organ system, organism, population, community, ecosystem, biosphere

2. Respond to stimuli

   • external stimuli leaves of plants follow passage of the sun
   • with loud noise your heartbeat increases, your blood pressure increases, brain directs blood vessels to dilate , that help to restore normal blood pressure

3. mantain homeostasis

   • mantenance of normal internal conditions in ln a cell or an organism by self-regulating mechanisms
   • e.g. human body temperature can rise with activity and can decline with inactivity

4. reproduce and grow and development

   • development, a time from egg is fertilized until death
     • grow is increase in size and number of cells
   • reproduction is passing a genetic information to next generation
     • genes contain DNA information
     • change in DNA composition
       • mutations is a basis of evolutionary change

5. aquire materials and energy

   • metabolism
     • all chemical reactions within a cell
   • photosynthesis
     • process of converting energy of the sun to chemical energy
       • PH produces organic molecules such as sugars, as the basis of the food chain for many other organisms

6. have evolutionary history

   • evolution is the process by which a population changes over time
     • every changed generation (with new variation) represents an adaptation to the environment