evolution and natural selection

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Across
  1. 1. drift the change in frequency of an existing gene variant in the population due to random chance.
  2. 3. an infectious microbe consisting of a segment of nucleic acid
  3. 5. effect an extreme example of genetic drift that happens when the size of a population is severely reduced.
  4. 7. evolution occurs when two or more species reciprocally affect each other's evolution through the process of natural selection.
  5. 10. single-celled, or simple, organisms that are invisible to the naked eye.
  6. 11. cells cells containing membrane-bound organelles
  7. 13. selection a mechanism of evolution
  8. 15. of genes a permanent change in the DNA sequence that makes up a gene
  9. 17. flow the movement of genes from one population to another population
  10. 18. how a new kind of plant or animal species is created.
  11. 19. reproduction the production of new organisms by the combination of genetic information of two individuals of different sexes
  12. 20. any heritable trait that helps an organism, such as a plant or animal, survive and reproduce in its environment.
Down
  1. 2. the study of embryo development
  2. 4. breeding choosing parents with particular characteristics to breed together and produce offspring with more desirable characteristics.
  3. 6. the dying out or extermination of a species.
  4. 8. variations changes and adaptations to the characteristics for survival and mating
  5. 9. cells single-celled organisms
  6. 12. effect reduction in genomic variability that occurs when a small group of individuals becomes separated from a larger population.
  7. 14. matching genes
  8. 16. reproduction a mode of reproduction in which a new offspring is produced by a single parent.