Evolution and Natural Selection

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Across
  1. 2. An explanation that is based on observation, experimentation, and reasoning.
  2. 3. Eukaryotes evolved from prokaryotes.
  3. 7. The actual age of the fossil given in years.
  4. 8. A microscopic single-celled organism that has neither a distinct nucleus with a membrane nor other specialized organelles.
  5. 10. A blood protein produced in response to and counteracting a specific antigen.
  6. 11. Looking at layers in sedimentary rock
  7. 12. The formation of new and distinct species in the course of evolution.
  8. 16. Members of a species compete for limited resources.
  9. 18. Your own body produces antibodies
  10. 20. Embryology is the study of embryos and their development.
  11. 22. The principle that events in the past occurred suddenly and were caused by different mechanisms than those operating today.
  12. 23. Asexual reproduction is a type of reproduction which does not involve the fusion of gametes or change in the number of chromosomes.
  13. 24. A method of dating rocks and minerals using radioactive isotopes.
  14. 25. Change in DNA that alters an allele
Down
  1. 1. An inherited blood disorder where red blood cells (RBCs) become sickle/crescent shaped.
  2. 4. A unit of heredity which is transferred from a parent to offspring and is held to determine some characteristic of the offspring.
  3. 5. You are given or passed antibodies
  4. 6. A cell whose nucleus unites with that of another cell to form a new organism.
  5. 9. Relating to, involving, or requiring an absence of free oxygen.
  6. 13. A method of breeding that allows only those individual organisms with desired characteristics to produce the next generation.
  7. 14. Change in allele frequency due to a chance event
  8. 15. When a population is separated, gene flow stops and creates a new species.
  9. 17. An organism consisting of a cell or cells in which the genetic material is DNA in the form of chromosomes contained within a distinct nucleus.
  10. 18. Relating to, involving, or requiring free oxygen.
  11. 19. The production of new living organisms by combining genetic information from two individuals of different types
  12. 21. An allele is one of two or more versions of a gene.