Evolution and Natural Selection

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Across
  1. 2. an extreme example of genetic drift that happens when the size of a population is severely reduced
  2. 4. a very simple microorganism that infects cells and may cause disease
  3. 7. organisms whose cells contain a nucleus and other membrane-bound organelles
  4. 8. asexual reproduction by a separation of the body into two new bodies
  5. 11. small single-celled organisms
  6. 12. type of structural modification made to a part of the body
  7. 16. when different organisms independently evolve similar traits
  8. 17. choosing parents with particular characteristics to breed together and produce offspring with more desirable characteristics
  9. 19. the process through which populations of living organisms adapt and change
  10. 20. the complete disappearance of a species from Earth
Down
  1. 1. a branch of science that is related to the formation, growth, and development of embryo
  2. 3. the direct transfer of DNA between two cells that are temporarily joined
  3. 5. When two organisms create a third organism through reproduction
  4. 6. a feature that a species inherited from an ancestor but that is now less elaborate and functional than in the ancestor
  5. 9. the process by which individuals compete for access to mates and fertilization opportunities
  6. 10. process within evolution that leads to the formation of new
  7. 13. one parent copies itself to form a genetically identical offspring
  8. 14. cases where two (or more) species reciprocally affect each other's evolution
  9. 15. matching genes
  10. 18. mechanisms of gene transfer from one population to another