Chapter 13

• Hybridization


  Crossing between dissimilar individuals
• Hybridization


  • Brings together the best characteristics of the parents
  • Results in offspring with new characteristics
• Inbreeding


  Crossing of individuals with similar characteristics
• Inbreeding


  • Maintains varieties of purebred dogs
  • Can change the DNA of an organism
• Genetic engineering


  Changing the DNA of an organism
• Genetic engineering


  1. DNA can be cut into shorter sequences by protein restriction enzymes

  2. Recombinant DNA is produced
• Recombinant DNA


  DNA that has been altered by combining genetic material from multiple sources
• Cell transformation


  Successful cell transformation is treated with antibiotics
• Bacteria


  Often contain small circular molecules of DNA known as restriction enzymes
• Figure 13-10 is produced in a drawing of recombinant DNA
• Recombinant DNA


  Produced by combining DNA from different sources
• Polymerase chain reaction


  Copies a particular gene (photo copy)
• Plasmid


  • Small circular DNA molecule
  • Has a gene that makes it possible to distinguish bacteria that contain it from those that don't
• Genetic marker allows possible to distinguish bacteria
• Transgenic


  Containing genes from other species
• Genetically identical


  A single cell
• Clone


  Cells produced from a single organism that contain genes from other organisms
• A member of a population of genetically identical cells produced from a single cell is a clone
• Selective breeding


  1. Produce the next generation with desired characteristics

  2. Allow only those characteristics that humans use to their advantage
• Artificial selection


  Selecting breeding, taking naturally occurring genetic variation in plants, animals and organisms to pass desired traits to the next generation
• Hybridization


  Bringing together dissimilar individuals to produce the next generation
• Inbreeding


  Continued breeding of similar individuals to maintain certain characteristics
• Genetic engineering


  Making changes in the DNA code of a living organism
• Restriction enzymes


  Each one cuts a specific sequence of nucleotides
• Gel electrophoresis


  1. A mixture of DNA fragments is placed on a gel

  2. Electric current is applied

  3. Positively and negatively charged fragments separate
• Aging can be viewed in terms of chronological age, biological age, psychological age, and social age
• Chronological age


  Measured by the number of years lived
• Biological age


  Predicted by the person's physical condition and by how well vital organ systems are functioning
• Psychological age


  Indicated by the person's ability and control in regard to memory, learning capacity, skills, emotions, and judgement
• Social age


  Measured by age-graded behaviours that conform to an expected social status and social roles within a particular culture or society
• These different types of aging within a person do not necessarily match
• Examples of mismatched ages

  • A person may have a chronological age of 80 years but a biological age of 60 years
  • A person with a chronic illness may have a biological age of 70 years but a much younger psychological age owing to an active and involved lifestyle
• There are several psychological and sociological theories of aging
• Not all theories acknowledge the importance of opportunity, ethnicity, gender, and social status
• As current generations of older adults move through life, many of the current ideas and theories about this period of life development will continue to be redefined