Manipulating Genomes

• 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
• In what type of therapy is recombinant DNA used?

  Gene therapy
• What is one issue associated with gene therapy?

  High costs
• What is another issue associated with gene therapy?

  Side effects
• What ethical considerations are raised by gene therapy?

  If we should offer genes as treatment
• Name one method for producing DNA fragments.

  Restriction endonucleases
• Name another method for producing DNA fragments.

  Reverse transcriptase
• Name another method for producing DNA fragments.

  The gene machine
• What is a restriction endonuclease?

  An enzyme
• What does a restriction endonuclease do when it recognizes a specific sequence?

  Cuts the DNA
• How does a restriction endonuclease cut DNA?

  By breaking bonds between nucleotides
• What is the result of a restriction endonuclease cutting a DNA molecule at two recognition sites?

  A DNA fragment
• Where are restriction endonucleases extracted from?

  From bacteria
• Why do bacteria use restriction endonucleases?

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

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

  DNA nucleotides
• After complementary DNA is created what happens to the mRNA molecule?

  An enzyme destroys it
• What is the new strand formed by reverse transcriptase called?

  Complementary DNA
• What enzyme builds the second DNA strand?

  DNA polymerase
• What is a key advantage of using the gene machine?

  It's much faster
• What is analysed from a protein to use the gene machine?

  The amino acid sequence
• What is worked out from the amino acid sequence of a protein?

  The corresponding mRNA sequence
• What is worked out from the mRNA code?

  DNA sequence
• After the DNA sequence is determined, what does a computer check?

  If the DNA is safe and ethical
• What does the gene machine start constructing?

  Short DNA strands
• What is the final step the gene machine does?

  Assembles the small strands into a DNA fragment
• What are the two types of gene cloning?

  In vivo and in vitro
• What are vectors?

  Molecules that a host wont recognise as foreign
• Why is bacteria a good host for gene cloning?

  It replicates rapidly
• What molecule is used to disguise DNA in bacteria?

  A plasmid
• What produces the gene fragments used in in vivo gene cloning?

  Restriction endonucleases
• What kind of ends do DNA fragments produced by restriction endonucleases have?

  Sticky ends
• What enzyme joins DNA fragments to plasmid nucleotides?

  DNA ligase
• What is a promoter?

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

  Detachment site for RNA polymerase
• What is transformation?

  Adding a plasmid to a host cell
• What is required for transformation?

  Calcium ions and heat shock
• After transformation, why might some bacteria not contain a recombinant plasmid?

  Plasmid may rejoin without DNA fragment