3 - RECOMBINANT DNA

• What is genetic engineering?

  Modification of an organism's genes
• How does transformation work in genetic engineering?

  By removing a gene from one organism and inserting it into another
• What is recombinant DNA?

  DNA combined from different sources
• What does the term "chimera" refer to in genetics?

  A DNA strand combined from different sources
• What is the most common recombinant process?

  Combining DNA from two different organisms
• What is a plasmid?

  A small circular DNA molecule
• Why are plasmids used in genetic engineering?

  They can carry DNA into bacterial cells
• What is the role of restriction enzymes in recombinant DNA technology?

  They cut DNA at specific sequences
• What are "sticky ends" in DNA?

  Overhangs left after DNA is cut
• What is the purpose of using reverse transcriptase in genetic engineering?

  To convert mRNA into complementary DNA
• What is a transgenic organism?

  An organism with DNA from another species
• What is gene knockout?

  A technique to disable a specific gene
• What are some methods to introduce foreign DNA into cells?

  Heat shock, electroporation, and microinjection
• What is the first step in transformation?

  Selecting a piece of DNA to insert
• What is a selectable marker in genetic engineering?

  A gene that allows identification of recombinant molecules
• What is the role of reporter genes?

  To confirm successful introduction of the vector
• What is the significance of plasmids being under relaxed control?

  They replicate independently of chromosomal DNA
• What is the maximum DNA size that bacterial plasmids can accept?

  5000 base pairs
• What are cosmids?

  Vectors that combine features of plasmids and bacteriophage
• What is the maximum DNA size that cosmids can accommodate?

  50 kilobases
• What is a yeast artificial chromosome (YAC)?

  A linear yeast chromosome that can incorporate large DNA
• What is the purpose of gene therapy?

  To correct genetic mistakes in cells
• What are some risks associated with recombinant DNA technology?

  Gene transfer to wild strains and antibiotic resistance
• What do the NIH Guidelines for recombinant DNA research detail?

  Safety practices and containment procedures
• What are the characteristics of a good vector in genetic engineering?

  • Ability to replicate independently
  • Contains a recognition sequence for restriction enzymes
  • Includes selectable markers
  • Small size for easy manipulation
• What are the applications of recombinant DNA technology?

  • Better crops (drought & heat resistance)
  • Recombinant vaccines (e.g., Hepatitis B)
  • Production of insulin and clotting factors
  • Gene therapy for genetic diseases
• What are the strengths and weaknesses of gene knockout techniques?

  Strengths:

  • Understand gene function
  • Develop targeted drug therapies

  
  

  Weaknesses:

  • Difficult in animals
  • Random insertion can disrupt key genes
• What are the methods of non-bacterial transformation?

  • Microinjection
  • Phage introduction
  • Electroporation
• What are the implications of recombinant DNA technology for the future?

  • Impact on agriculture and health
  • Potential for new treatments and crops
  • Ethical considerations in genetic modifications