Unit 13: Changes Over Time

1234567891011121314151617181920
Across
  1. 2. a group of similar organisms that can mate with each other and produce fertile offspring.
  2. 4. is a well tested concept that explains a wide range of observations.
  3. 5. is the process by which individual that are better adapted to their environment are more likely to survive and reproduce than other members of the same species.
  4. 6. similar structures that related species inherited from common ancestors.
  5. 8. a hollow space in the sediment in the shape of an organism or part of an organism
  6. 10. gradual change in a species over time.
  7. 11. any difference between individual of the same species.
  8. 13. is a diagram that shows how scientist thin different groups of organisms are related.
  9. 14. which are unstable elements that decay, or break down, into different elements
  10. 16. is a copy of the shape of the organism that make the mold.
  11. 17. minerals dissolved in the water soak into the buried remains, the minerals replace the remains, changing them into rock.
  12. 19. a trait that helps an organism survive and reproduce
  13. 20. the time it take s for half of the atoms in a sample to decay.
Down
  1. 1. fossils that scientist have collected
  2. 3. account for the gaps in the fossil record. Rapid evolution
  3. 7. proposes that evolution occurs gradually over time.
  4. 9. Rocks that are found near the fossil contain radioactive elements, they test this element to determine the age
  5. 12. can only be used when rock layers have been preserved in their original sequence
  6. 15. no members of a particular species is still living.
  7. 18. is the preserved remains or remains of an organism that lived in the fast.