Solutions
3 steps in the PCR cycle Correct Answers 1. denaturation
2. annealing
3. extension/elongation
after transformation what happens to bacteria? Correct Answers
it is plated on a medium with ampicillin and X gal
*only cells with ampr can grow on plates*
ampr Correct Answers can grow in the presence of ampicillin
annealing Correct Answers allows to come in and bind
argobacterium Correct Answers gets transformed to
incorporate plasmid in it
blue colonies mean the plasmid is? Correct Answers non
recombinant
-bgal is present
-ampr is present
blunt ends Correct Answers where enzymes cut both strands of
DNA straight across
ex: PvuII makes these cuts
cDNA library Correct Answers library containing DNA
sequences complementary to mRNA (DNA sequences that are
expressed)
, cDNA library: create cDNA Correct Answers degrades RNA
-strands of thymines added in
-reverse transcriptase (type of DNA pol) and dNTP are added
because there needs to be a primer added bc of thymines
-mRNA-DNA hybrid is formed
-RNase is added and breaks up RNA into fragments
-DNA polymerase comes in and fills in the gaps and put more
DNA fragments in
-DNA ligase seals up all the DNA and now you have 2 strands
(one 5'→3' and the other 3'→5')
cDNA library: isolate mRNA Correct Answers 1. a special
column containing short oligoi(dT) chains linked to cellulose
2. mRNAs have polyA tails. total cellular RNA is isolated from
cell and passed through the column
3. poly(A) tails of mRNA molecules pair with the oligold(T)
chains and the mRNA is retained in the column whereas the rest
of the RNA passes through
4. mRNA can be washed from the column by adding a buffer
that breaks the hydrogen bonds between the polyA tail and
oligoT chains which leaving only mRNA with polyA tails
characteristics of STR Correct Answers each STR located on
diff chromosome
-assort independently
-probability of 2 people having same profile is less than 1 in 10
billion
**Graphs can be used to determine presence of a suspect at a
crime scene*