Natural selection/topic 4

• why do we Genetically modify crops?

  • to improve fruit size and quality
  • for disease resistance
  • for insect resistance
  • for herbicide resistance
• what are some things selectively bred for?

  • Cows to produce lots of meat or milk
  • Crops to be resistant to diseases
  • to have friendly cats and dogs as pets
  • to have plants with large or unusual flowers
• Binomial naming system

  Naming species by their genus and species names, e.g. Homo sapiens
• what is genetic engineering?


  modifying an organisms genome to introduce more desirable characteristics
• what is a vector?

  something used to transfer DNA into a cell
• what are restriction enzymes?


  enzymes that recognize specific sequences of DNA and cut them at these points (used in genetic engineering)
• what are ligase enzymes?

  enzymes used to join 2 pieces of DNA at their sticky ends (used in genetic engineerin)
• what are the 2 types of vector?

  plasmids and viruses
• what is a plasmid?


  small circular molecules of DNA that can be transferred between bacteria
• what is a virus?


  they insert DNA into organisms they infect
• how is genetic engineering useful in agriculture?

  crops can be modified to be resistant to herbicides so when weedkiller is used it will kill weeds without affecting the crops themselves
• how can genetic engineering be useful in medicine?

  can engineer bacteria to to produce human insulin
• what are some downsides to genetic engineering?

  may cause animals to suffer from health problems later in life and genetically modified crops could affect human health
• what is natural selection?

  individuals with characteristics that make them better adapted to survive in the enivronment theyre in survive
• how is bacteria evidence for evolution?

  the organisms adaptation over time to develop resistance to certain drugs (antibiotics)
• how are fossils evidence for evolution?

  graudal change in the organims fossil over time provides evidence for adaptation
• what are the 5 kingdoms?

  animals,plants,protists,fungi,prokaryotes
• what are the subdivided groups of the kingdoms?

  phylum,class,order,family,genus,species
• what are the 3 domains?

  arcaea,bacteria,eukarya
• what is selective breeding?

  humans artifically selecting plants/animals with desirable characteristics then breeding them to develop offspring with better charcteristics
• what are some disadvantages to selective breeding?

  • can lead to inbreeding which can cause harmful genetic defects
• what are hominids?


  human beings and their ancestors
• how old is ardi?

  4.4 milli years
• what changed in hominid fossils over time?

  • brain size increasing
  • shorter arms
  • longer legs
  • walking more upright