Natural selection

• independant variable (IV)


  the thing being changed in an experiment
• Dependant variable (DV)


  the thing being measured in an experiment
• Control (C)

  the thing that stays the same (valid) in an experiment
• variation - the differences in a population of organisms
• selection pressure - a factor within an environment that effects an organisms ability to survive and/or reproduce
• animal classifications


  Kingdom

  Phylum

  Class

  Order

  Family

  Genus

  Species
• binomial name - genus and species name, to give each animal a seperate name
• 3 domain system


  Archaea - primitive bacteria

  Bacteria - true bacteria

  Eukaryota - protists, fungi, plants, and animals
• evidence for human evolution

  skull volume increases over millions of years

  height increases

  strength increases
• issues with fossil records

  few organisms form fossils

  specific conditions are needed for fossils to form

  often gaps in fossil records
• selective breeding - the process of breeding animals or plants to produce offspring with desirable characteristics
• selective breeding advantages


  can eliminate diseases

  can create new varieties

  doesn't involve genetic modification
• selective breeding disadvantages

  loss of variety

  takes a long time

  can change natural evolution
• genetic engineering is the process of modifying the genetic material of an organism to produce a desired trait
• gene - a sequence of DNA that codes for a specific protein
• plasmid - a small circular DNA molecule that is found in bacteria
• genetic modification steps (GM)

  identify desired gene

  cut gene out using restriction enzyme (gene will now have sticky ends)

  stick desired gene into a plasmid using ligase

  place GM plasmid into a vector
• cell - the basic unit of life in all organisms, consisting of a nucleus and cytoplasm
• tissue - a group of cells that work together to do the same job
• organ - a group of tissues that work together to do the same job
• advantages of tissue culture

  can be used to treat cancer

  can be used to duplicate plants

  can study viruses that can't be replicated elsewhere
• callus - a clump of undifferentiated cells