BIOL 4003; Exam 3 questions and
answers already passed
Gene cloning uses - correct answer ✔✔
Describe how to clone genes into vectors - correct answer ✔✔ 1. chromosomal DNA is isolated
+ digested by restriction enzyme
2. Plasmid DNA also cut by the same restriction enzymes that results in 2 ends complementary
to that of the cDNA fragment sticky ends
3. Digested cDNA + plasmid DNA mixed in solution under conditions that promote the binding
of sticky ends via complementary base pairing
4. DNA ligase added into solution to promote or catalyze covalent bonding of the two adjacent
backbones
cDNA - correct answer ✔✔ 1. Complementary DNA : made using RNA template as starting
material
2. cDNA is made from mRNA via reverse transcriptase
- RNA sample provides starting point for DNA cloning
Reverse transcriptase - correct answer ✔✔ uses RNA as a template that results in formation of
double-stranded DNA
cDNA synthesis steps - correct answer ✔✔ 1. Add a poly-dT primer that binds to the polyA tail
of mRNA
2. Add reverse transcriptase + dNTPs ro synthesize a complementary DNA strand
3. Add RNaseH to cut up the RNA and generate RNA primers
, 4. Add DNA polymerase I and DNA ligase to synthesize the second DNA strand (dscDNA)
5. After double stranded cDNA is made, it can then be inserted into a vector
a. A poly-dT primer that binds to the 3' end of eukaryotic mRNAs.
b. Reverse transcriptase catalyzes the synthesis of a complementary DNA strand (cDNA)
c. RNaseH digests the mRNA into short pieces that are used as primers by DNA polymerase I to
synthesize the second DNA strand
d. the 5' to 3' exonuclease function of DNA polymerase I removes all of the RNA prmers except
the one at the 5' end (because..there is no primer upstream from this site).
- subsequent addition of RNase will eventually remove this primer
e. After double stranded cDNA is made, it can then be inserted into a vector
which step(s) are not needed to make a cDNA (complementary DNA) library?
a. attach linkers to the cDNA (oligonucleotide linkers that contain restriction site)
b. Cut cDNA and vector with a restriction enzyme and ligate the cDNA into the vector
c. Isolate chromosomal DNA and digest with a restriction enzyme
d. Isolate mRNA and make a cDNA using reverse transcriptase and a poly-dT primer - correct
answer ✔✔ C : Restriction enzymes cut the cDNA
Which of the following may be used as a vector in a gene-cloning experiment?
a. mRNA
answers already passed
Gene cloning uses - correct answer ✔✔
Describe how to clone genes into vectors - correct answer ✔✔ 1. chromosomal DNA is isolated
+ digested by restriction enzyme
2. Plasmid DNA also cut by the same restriction enzymes that results in 2 ends complementary
to that of the cDNA fragment sticky ends
3. Digested cDNA + plasmid DNA mixed in solution under conditions that promote the binding
of sticky ends via complementary base pairing
4. DNA ligase added into solution to promote or catalyze covalent bonding of the two adjacent
backbones
cDNA - correct answer ✔✔ 1. Complementary DNA : made using RNA template as starting
material
2. cDNA is made from mRNA via reverse transcriptase
- RNA sample provides starting point for DNA cloning
Reverse transcriptase - correct answer ✔✔ uses RNA as a template that results in formation of
double-stranded DNA
cDNA synthesis steps - correct answer ✔✔ 1. Add a poly-dT primer that binds to the polyA tail
of mRNA
2. Add reverse transcriptase + dNTPs ro synthesize a complementary DNA strand
3. Add RNaseH to cut up the RNA and generate RNA primers
, 4. Add DNA polymerase I and DNA ligase to synthesize the second DNA strand (dscDNA)
5. After double stranded cDNA is made, it can then be inserted into a vector
a. A poly-dT primer that binds to the 3' end of eukaryotic mRNAs.
b. Reverse transcriptase catalyzes the synthesis of a complementary DNA strand (cDNA)
c. RNaseH digests the mRNA into short pieces that are used as primers by DNA polymerase I to
synthesize the second DNA strand
d. the 5' to 3' exonuclease function of DNA polymerase I removes all of the RNA prmers except
the one at the 5' end (because..there is no primer upstream from this site).
- subsequent addition of RNase will eventually remove this primer
e. After double stranded cDNA is made, it can then be inserted into a vector
which step(s) are not needed to make a cDNA (complementary DNA) library?
a. attach linkers to the cDNA (oligonucleotide linkers that contain restriction site)
b. Cut cDNA and vector with a restriction enzyme and ligate the cDNA into the vector
c. Isolate chromosomal DNA and digest with a restriction enzyme
d. Isolate mRNA and make a cDNA using reverse transcriptase and a poly-dT primer - correct
answer ✔✔ C : Restriction enzymes cut the cDNA
Which of the following may be used as a vector in a gene-cloning experiment?
a. mRNA
