Biology

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Across
  1. 6. first eukaryotes evolved from 1 prokaryote living within another
  2. 7. single species or multiple species die out
  3. 12. organisms on Earth have been changing as seen in preserved organisms Convergent evolution-organisms under similar environmental pressures evolve similarly
  4. 13. inner most layer-digestive system, trachea, lungs
  5. 14. early stage of embryonic development, occurs after fertilization of egg + formation of zygote
  6. 16. organisms have unused organs or structures
  7. 17. same structures can evolve for different uses depending on environmental demand
  8. 19. single species or group diversifies into many distinct forms
  9. 21. outermost layer-skin, hair, nails
  10. 22. different structures can evolve to fulfill similar demands based on environmental demands
Down
  1. 1. major group of animals characterized by their embryonic development Derived character - feature present in organism that was absent in last common ancestor group Protostome - characterized from embryonic development - phyla
  2. 2. 2 species living in close proximity evolve in response to each other
  3. 3. genus species used to make scientific name for organism
  4. 4. master control gene, determines placement and activation development in organism clocks- Randomocks-random mutations accumulate over time at a consistent rate-# of mutations differences can be used to predict when an evolutionary split occurred
  5. 5. small changes in a population
  6. 8. early stage of embryonic development - follows Blastula - formation of the layers, Ectoderm - mesoderm - endoderm Zygote - initial cell formed after fertilization of egg
  7. 9. small changes over time compound into large changes
  8. 10. section Binomial nomenclature-tries to show ancestry
  9. 11. long periods of equilibrium interrupted by rapid change
  10. 15. middle layer in germ layer-gives variety of structures in body
  11. 18. study of embryos and their development, formation, growth, development
  12. 20. a scientific naming system used to identify organisms