Card Set Information

2015-04-12 16:51:39
biol189 ex3 dna
EX 3 DNA technology
Show Answers:

  1. Distinguish among recombinant DNA, genetically modified organisms, and transgenic organisms.
    • -DNA Tech: manipulation of
    • genetic material, even moving genes from one organism to another

    • -Recombinant DNA: a DNA
    • molecules that derives from two or more sources

    • -Genetically modified organism:
    • organism with one or more genes introduced using DNA technology

    • -Transgenic organism: A GMO
    • which has genes from more than one organism
  2. What is a restriction enzyme? Make sure you understand restriction maps and ‘sticky ends’.
    Reaction enzyme: proteins that cleave DNA at restriction sites Sticky Ends: any DNA cut by a particular restriction enzyme can stick to any other cut by the same enzyme
  3. What is a plasmid, where can they come from, and what organisms have them?
    A genetic structure in a cell that can replicate independently of the chromosome, typically a small circular DNA strand in the CYTOPLASM of a bacterium
  4. Describe the process of creating a recombinant DNA molecule.
    • 1.    
    • getting
    • smaller pieces of DNA to wok with restriction enzymes

    • 2.    
    • separating
    • fragments: gel electrophoresis

    • 3.    
    • find
    • a particular sequence in the genome: nucleic acid probes

    • 4.    
    • making
    • many copies of the DNA: cloning by biological vector or polymerase chain
    • reaction
  5. What is gel electrophoresis, what is its purpose, and how does it work?
    Separating molecules by size, charge etc -measures movement based on a standard -placed in gel and move by electrical charge
  6. What are the two ways to clone a gene?
    • 1.    
    • vector
    • such as bacteria, yeast, cell culture

    • -gene cleaved out of original genome using a particular
    • restriction enzyme

    • -gene inserted into bacteria plasmid (vector) cut with the
    • same enzyme to transfer (recombinant DNA) by shaking them together

    •        2.  
    • Polymerase chain reactions (PCR)

    •                   -clones of DNA sequence
    • without a biological vector
  7. Describe how a gene can be cloned in a
    biological vector.
    • 1.    
    • special
    • engineering plasmid and DNA of interest cut with same restriction enzyme and
    • mixed together, some combine

    • 2.    
    • mixtures
    • is exposed to a biological vector such as yeast or bacteria.  Some vectors pick up DNA

    • 3.    
    • individual
    • vectors are screened to identify those which picked up a plasmid which
    • contained the DNA of interest

    • 4.    
    • These
    • selected vectors are allowed to reproduce making more copies of the DNA of
    • interest
  8. Describe how the polymerase
    chain reaction (PCR) can be used to amplify genes.
    PCR produces copies from one sample

    •                   -primer(short
    • sequence of dna to be amplified)

    •                   -target
    • sequence (dna)

    •                   -dna
    • pol (heat-stable version-TAQ Polymerase)

    •                   -nucleotides
    • monomers



    •                   -heated
    • to 95 C, so dna denatures to single strands

    •                   -cools,
    • primers attach to their complimentary sequence

    •                   -dna
    • pol adds nucleotides to finish complimentary strand

    •                   -more
    • rounds yield more copies
  9. What is a nucleic acid probe used to accomplish?
    Nucleic acid probe: finding the correct gene

    •                   -single
    • stranded sequence of interest is labeled (dye, radiation)

    •                   -when
    • mixed with the sample, it sticks to its compliment

    •                   -any
    • single stranded sequence

    • ex. 
    • CCGGTTAA PROBE à DNA sequence labeled


  10. Understand how forensic tests and
    paternity analyses are based on, and how the chance of mistaken identity error
    can be reduced.
    • -based on
    • highly variable non-coding sequences

    • -cut with
    • restriction enzymes

    • -many
    • radioactive probes used to determine which fragments are present

    • -compared to
    • suspects

    • -very low
    • chance of error

    • -based on
    • single tandem repeats (STR’s) non-coding DNA more variable than coding DNA
  11. What is a genome?
    • The study of
    • entire genomes

    • About 4000
    • species sequenced (mostly prokaryotes)
  12. How is information in the genome
    apportioned between coding and non-coding DNA?
    Human genome:

    • Protein coding
    • DNA 1-15%

    • Non coding DNA
    • 98.5-99%
  13. What are the types of coding and
    non-coding DNA?
    • Non-coding
    • DNA:

    • -24% introns
    • and regulatory sequence

    • -15% structural
    • DNA around centromeres or ends (telomoeres); mostly simple sequence repeats

    • -44%
    • transposable elements (jumping genes)
  14. What is the biggest reason that
    mammalian cloning is difficult?
    • Humans are
    • more complex with approx. 100,000 genes
  15. What is methylation, and what does it do
    to genes?
    • Passing of a
    • chemical fragment called methyl group from one molecule to another.

    • It silences a
    • gene
  16. Potential exam question: Why is a random mutation
    unlikely to affect a protein? Include the approximate percentages for the
    categories of DNA discussed in class in your answer.