7 life processes

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Across
  1. 3. a journey from small to large
  2. 5. nature's way of passing the torch to the next generation
  3. 7. discreet removal of useless substances
Down
  1. 1. the force behind your journey
  2. 2. the body's fuel
  3. 4. the silent exchange of gases
  4. 6. the key to understanding the world around you