BI CFA: Problems 6-8: Molecular & Forensics

A short unit check. Enter your Student ID and answer each item. This is practice, not a grade.

1. 1. A restriction enzyme is used in cloning to:

   ACut DNA at a specific sequenceBMake many copies of a DNA regionCJoin two DNA fragments togetherDRead the order of the DNA bases

2. 2. A plasmid and an insert are both cut with EcoRI. Cutting both with the same enzyme gives:

   ATwo pieces of exactly the same lengthBA plasmid that needs no ligaseCSticky ends that match and pair upDEnds that must be filled in first

3. 3. A cut plasmid is mixed with ligase, but no insert is added. What happens to most of the plasmid?

   AIt is cut into smaller piecesBIt closes back on itselfCIt is copied many timesDIt stays a straight line

4. 4. Bacteria are plated on agar containing an antibiotic. Colonies grow only where cells took up the plasmid. The plasmid part that lets them survive is:

   AAn origin of replicationBExtra nutrients the cells can useCA gene for a glowing marker proteinDAn antibiotic-resistance gene

5. 5. In a transformation lab you also spread untransformed cells on an antibiotic plate. What does that plate check?

   AHow many cells took up the plasmidBThat the antibiotic is workingCHow well the transformation workedDThat the cells are competent

6. 6. Transformation plates go into a 37 degree C incubator overnight. Why that temperature?

   AIt is close to where E. coli grows bestBIt softens the agar for spreadingCIt matches the temperature of the heat shockDIt activates the plasmid's resistance gene

7. 7. DNA moves toward the positive end of a gel because DNA is:

   APushed through the pores of the agaroseBLighter than the buffer around itCNegative because of its phosphate groupsDPulled along by the loading dye it is mixed with

8. 8. Chain of custody documentation for evidence records:

   AWho handled the item and when it movedBThe photographs taken at the sceneCThe lab method used and the final resultDThe suspect's statement about the item

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