BIMM 100 Midterm 2 questions and
answers rated A+
Although transposable elements and short tandem repeats (STRs) are repetitive DNAs, they
differ in that _____.
a. the repeated unit in STRs is clustered one after another; transposable element repeats are
scattered throughout the genome
b. STRs occur within exons; transposable elements occur within introns
c. STRs occur within introns; transposable elements occur within exons
d. the repeated unit in STRs is much larger than the repeated unit of transposable elements -
correct answer ✔✔ a. the repeated unit in STRs is clustered one after another; transposable
element repeats are scattered throughout the genome
Retrotransposons _____.
1. are found only in animal cells
2. use an RNA molecule as an intermediate in transposition
3. contribute a significant portion of the genetic variability seen within a population of gametes
- correct answer ✔✔ 2. use an RNA molecule as an intermediate in transposition
Because they both produce a reverse transcriptase, long interspersed nuclear elements (LINEs)
as transposable elements may be related to _____.
a. poliovirus
b. retroviruses
c. parasitic bacteria
d. plasmids - correct answer ✔✔ b. retroviruses
, A principal problem with inserting an unmodified mammalian gene into a plasmid and then
getting that gene expressed in bacteria is that _____.
a. bacteria translate only mRNAs that have multiple messages
b. prokaryotes use a different genetic code from that of eukaryotes
c. bacteria cannot remove eukaryotic introns
d. bacterial RNA polymerase cannot make RNA complementary to mammalian DNA - correct
answer ✔✔ c. bacteria cannot remove eukaryotic introns
Bacterial cells protect their own DNA from restriction enzymes (endonucleases) by _____.
a. using DNA ligase to seal the bacterial DNA into a closed circle
b. forming "sticky ends" of bacterial DNA to prevent the enzyme (endonuclease) from attaching
c. adding histones to protect the double-stranded DNA
d. adding methyl groups to restriction sites. - correct answer ✔✔ d. adding methyl groups to
restriction sites.
What is the most logical sequence of steps for splicing foreign DNA into a plasmid and inserting
the plasmid into a bacterium?
I. Transform bacteria with a recombinant DNA molecule.
II. Cut the plasmid DNA using restriction enzymes (endonucleases).
III. Extract plasmid DNA from bacterial cells.
IV. Hydrogen-bond the plasmid DNA to nonplasmid DNA fragments.
V. Use ligase to seal plasmid DNA to nonplasmid DNA. - correct answer ✔✔ III, II, IV, V, I
answers rated A+
Although transposable elements and short tandem repeats (STRs) are repetitive DNAs, they
differ in that _____.
a. the repeated unit in STRs is clustered one after another; transposable element repeats are
scattered throughout the genome
b. STRs occur within exons; transposable elements occur within introns
c. STRs occur within introns; transposable elements occur within exons
d. the repeated unit in STRs is much larger than the repeated unit of transposable elements -
correct answer ✔✔ a. the repeated unit in STRs is clustered one after another; transposable
element repeats are scattered throughout the genome
Retrotransposons _____.
1. are found only in animal cells
2. use an RNA molecule as an intermediate in transposition
3. contribute a significant portion of the genetic variability seen within a population of gametes
- correct answer ✔✔ 2. use an RNA molecule as an intermediate in transposition
Because they both produce a reverse transcriptase, long interspersed nuclear elements (LINEs)
as transposable elements may be related to _____.
a. poliovirus
b. retroviruses
c. parasitic bacteria
d. plasmids - correct answer ✔✔ b. retroviruses
, A principal problem with inserting an unmodified mammalian gene into a plasmid and then
getting that gene expressed in bacteria is that _____.
a. bacteria translate only mRNAs that have multiple messages
b. prokaryotes use a different genetic code from that of eukaryotes
c. bacteria cannot remove eukaryotic introns
d. bacterial RNA polymerase cannot make RNA complementary to mammalian DNA - correct
answer ✔✔ c. bacteria cannot remove eukaryotic introns
Bacterial cells protect their own DNA from restriction enzymes (endonucleases) by _____.
a. using DNA ligase to seal the bacterial DNA into a closed circle
b. forming "sticky ends" of bacterial DNA to prevent the enzyme (endonuclease) from attaching
c. adding histones to protect the double-stranded DNA
d. adding methyl groups to restriction sites. - correct answer ✔✔ d. adding methyl groups to
restriction sites.
What is the most logical sequence of steps for splicing foreign DNA into a plasmid and inserting
the plasmid into a bacterium?
I. Transform bacteria with a recombinant DNA molecule.
II. Cut the plasmid DNA using restriction enzymes (endonucleases).
III. Extract plasmid DNA from bacterial cells.
IV. Hydrogen-bond the plasmid DNA to nonplasmid DNA fragments.
V. Use ligase to seal plasmid DNA to nonplasmid DNA. - correct answer ✔✔ III, II, IV, V, I
