DNA technology

• What is recombinant DNA?

  Combined DNA of two or more organisms
• What are organisms called that contain recombinant DNA?

  Transgenic
• Why can transgenic organisms translate DNA from other organisms?

  The genetic code is universal
• What is one application of recombinant DNA?

  Gene therapy
• What is the purpose of gene therapy?

  To treat or cure a disease
• What are some issues associated with gene therapy?

  • Costs
  • Side effects
  • Ethical considerations
• What are three ways a DNA fragment can be produced?

  Restriction endonucleases, reverse transcriptase, gene machine
• What is the function of restriction endonucleases?

  To cut DNA at specific sequences
• How do restriction endonucleases recognize where to cut the DNA?

  By identifying a specific recognition sequence
• What type of bonds do restriction endonucleases break?

  Bonds between adjacent nucleotides
• Where are restriction endonucleases extracted from?

  Bacteria
• Why do bacteria use restriction endonucleases?

  To defend against pathogens
• What molecule is used to reconstruct a corresponding DNA segment using reverse transcriptase?

  mRNA
• What does reverse transcriptase add to the mRNA molecule?

  DNA nucleotides
• What is the name of the new strand that is formed using reverse transcriptase?

  Complementary DNA
• Which enzyme destroys the mRNA molecule after the first DNA strand is built in reverse transcription?

  An enzyme
• Which enzyme builds the second DNA strand in reverse transcription?

  DNA polymerase
• What is an advantage of using the gene machine to produce DNA fragments?

  It's much faster
• Why is the gene machine faster than using enzymes?

  It does not rely on enzymes
• What are the steps involved in using the gene machine to produce a gene?

  • The amino acid sequence of a protein is analysed
  • The corresponding mRNA sequence worked out
  • The mRNA code is then used to work out DNA sequence
  • Computer checks the DNA is safe and ethical
  • The machine starts constructing short DNA strands
  • Assembles the small strands into a whole DNA fragment
• What are the two main types of gene cloning?

  In vivo and in vitro
• What are vectors in gene cloning?

  Molecules that carry DNA into a host
• Why is bacteria a good host for gene cloning?

  It replicates rapidly
• How is DNA disguised when using bacteria as a host?

  In a plasmid
• What kind of gene fragments are used in in vivo gene cloning?

  Fragments produced using restriction endonucleases
• What are sticky ends in DNA fragments?

  Overhanging single-stranded DNA sequences
• What enzyme joins DNA fragments to plasmid nucleotides?

  DNA ligase
• What is a promoter in gene cloning?

  Binding site for RNA polymerase
• What is the function of a terminator sequence?

  Detachment site for RNA polymerase
• What is transformation in the context of gene cloning?

  Adding a plasmid to a host cell
• What two things does transformation require?

  Calcium ions and a heat shock
• What are some possible outcomes after transformation, and why is identifying recombinant plasmids important?

  • Some bacteria may not contain a recombinant plasmid because the plasmid rejoined without incorporating DNA fragments.
  • Some DNA fragment can also join together and not to plasmid.
  • Some bacteria will also not take up recombinant plasmid.
• What does the first step of identifying bacteria after transformation involve?

  Identifying antibiotic resistance gene
• How can scientists identify which bacteria took up a recombinant plasmid?

  Another antibiotic resistance marker
• What happens to the bacteria that took up recombinant plasmid when using antibiotic resistance markers?

  They die
• What method is used to identify recombinant DNA without killing the bacteria?

  Replica plating
• How do scientists use fluorescents to identify recombinant DNA?

  Bacteria with recombinant DNA won't display the observable property
• How do scientists use enzymes to identify recombinant DNA?

  Bacteria with recombinant DNA won't display the observable property
• Where does in vitro gene cloning take place?

  Outside a living organism
• What three things does the polymerase chain reaction require?

  DNA nucleotide, DNA polymerase and primers