biology

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Across
  1. 6. the process where organisms that are fitter for an environment survive more and produce more offspring
  2. 8. the remains of a prehistoric plant or animal that is embedded in rock and preserved
Down
  1. 1. the genetic material of an organism
  2. 2. the process by which different kinds of living organism are believed to have developed from earlier forms during the history of the earth
  3. 3. an early type of animal or plant from which others have evolved
  4. 4. a unit of heredity that is passed down from parent to offspring
  5. 5. the changing of the structure of a gene
  6. 7. an arm or a leg of an animal or a birds wing