science

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Across
  1. 2. small opening in the middle of the iris through which light enters the eye
  2. 5. collection of all the organisms that live in a particular place, together with their nonliving environment
  3. 7. term used to refer to a species that died out
  4. 9. smallest unit of most compounds
  5. 11. group of similar cells that perform a particular function
  6. 12. a fertilized egg
Down
  1. 1. chemical substance that an organism requires to live
  2. 3. science that seeks to understand the living world
  3. 4. scientific study of heredity'
  4. 6. evidence; information gathered from observations
  5. 8. preserved remains or evidence of an ancient organism
  6. 10. early developmental stage of a sporophyte plant