Exam Notes

Artificial Selection

  • Artificial Selection: Intentional breeding for certain traits determined by humans, not environmental factors.
  • Nature provides variation; humans select specific variations.
  • Comparison of Natural and Artificial Selection:
    • Environmental Influence:
      • Natural: Environment influences survival and reproduction.
      • Artificial: Humans influence traits.
    • Processes that change traits:
      • Natural: Traits are genetically inherited and improve an organism's chance to survive and reproduce over a long time. Requires diversity of traits.
      • Artificial: Selected trait is desirable to breeders and happens quickly.

Homologous Structures

  • Homologous Structures: Structures with different mature forms that develop from the same embryonic tissues.
  • Examples: Forelimbs of humans, cats, whales, and bats.
    • These forelimbs share a similar bone structure: Humerus, Radius, Ulna, Carpals, Metacarpals, and Phalanges.

Vestigial Structures

  • Vestigial Structures: Organs or structures remaining in an imperfect condition or form, no longer used.
  • Examples: penguin wings, whale hip bones.
  • Vestigial Organs: Structures that seem to be "left over" from a previous ancestor and serve no purpose in the living organism.
  • Vestigial structures are historical remnants of structures that had important functions in ancestors.
  • Example: Appendix

Genetic Similarities in DNA (Biological Molecules)

  • Different species share similar genes in their DNA.
  • More closely related species share more of the same genes.
  • Darwin did not have DNA data; DNA was discovered later (1960s).

Plant Classification

  • The plant kingdom contains a diversity of organisms.

Nonvascular Seedless Plants

  • Lack vascular tissue (specialized tissue that transports water, nutrients, and food).
  • Do not have true roots, stems, or leaves, but may have