8.4.1 Recombinant DNA technology

• What is recombinant DNA technology?

  Transfer of DNA fragments between organisms
• Why can transferred DNA be translated in transgenic organisms?

  Genetic code and mechanisms are universal
• How are DNA fragments produced using restriction enzymes?

  They cut DNA at specific recognition sequences

  
• What do restriction enzymes create when they cut DNA in a staggered fashion?

  Sticky ends with single stranded overhangs

  
• How can DNA fragments be produced from mRNA?

  By using reverse transcriptase to synthesize cDNA
• What is an advantage of obtaining genes from mRNA instead of DNA?

  More mRNA is available for extraction
• Why is mRNA advantageous for prokaryotes in gene expression?

  Introns are removed in mRNA, allowing translation
• What does a gene machine do?

  Synthesizes DNA fragments quickly and accurately
• What is an in vitro technique for amplifying DNA fragments?

  Polymerase chain reaction (PCR)
• What is an in vivo technique for amplifying DNA fragments?

  Culturing transformed host cells
• What is the first step in PCR?

  Heating the mixture to 95°C to separate strands
• What happens at 55°C during PCR?

  Primers bind to the DNA template strand
• What occurs at 72°C in PCR?

  DNA polymerase joins adjacent nucleotides
• What is the role of primers in PCR?

  They allow DNA polymerase to start synthesis

  
• Why do DNA replication stops in PCR?

  Limited number of primers and nucleotides

  
• What are the steps to amplify DNA fragments in vivo?

  1. Add promoter and terminator regions
  2. Insert DNA fragments into vectors
  3. Transform host cells with vectors
  4. Detect transformed cells using marker genes
  5. Culture transformed host cells
• Why are promoter regions added to DNA fragments?

  To allow RNA polymerase to bind and start transcription

  
• What is the purpose of terminator regions in DNA fragments?

  To ensure transcription stops at the end of a gene
• What is the role of vectors in recombinant DNA technology?

  To transfer DNA into host cells
• How do enzymes assist in inserting DNA fragments into vectors?

  They cut vector DNA to create compatible ends

  
• How are host cells transformed using vectors?

  Plasmids enter cells or viruses inject DNA
• Why are marker genes inserted into vectors?

  To detect genetically modified cells or organisms
• How can recombinant DNA technology be useful in medicine?

  GM bacteria produce human proteins like insulin
• How can recombinant DNA technology benefit agriculture?

  GM crops resistant to herbicides and pests
• What is gene therapy?

  Introduction of new DNA to correct genetic disorders
• What are some issues associated with gene therapy?

  Short-lived effects and immune responses
• Why might humanitarians support recombinant DNA technology?

  Increased food production reduces famine risk
• Why might environmentalists oppose recombinant DNA technology?

  Risk of creating herbicide-resistant superweeds
• What are the ethical, financial, and social issues of recombinant DNA technology?

  • Ethical concerns about GMOs and health
  • Financial implications for farmers and companies
  • Social impact on food security and access
• What is a common mistake regarding recombinant DNA technology?

  Confusing the genetic code with DNA universality
• What is a common mistake regarding PCR and DNA polymerase?

  Confusing joining bases with joining nucleotides
• What is a common mistake regarding restriction enzymes?

  Believing they cut only the gene itself
• What is a common mistake regarding promoter and terminator regions?

  Confusing them with start and stop codons