Genetics Exam questions and
answers graded A+
What are the 4 components required for DNA synthesis? - ANS✅✅dNTPs (A,G,C,T), DNA template
strand and primer, DNA polymerase, Mg 2+ (optimizes DNA polymerase activity)
Which direction does DNA synthesize? - ANS✅✅5'->3'
DNA POL 1 - ANS✅✅Catalyzes formation of phosphodiester bond between the last and incoming
nucleotides. Degrades RNA primer via 5'->3' exonuclease.
The energy used by DNA POL 1 is derived from... - ANS✅✅the release of two of the three
phosphates of the dNTP.
Which DNA polymerase has 5'-3' polymerase activity? - ANS✅✅I, II, III
Which DNA polymerase has 3'->5' (exonuclease) error correction/ proof reading activity? -
ANS✅✅I, II, III, IV, V
3'->5' exonuclease subunit of DNA pol III - ANS✅✅Epsilon
Polymerase subunit of DNA pol III - ANS✅✅Alpha
Subunit of DNA pol III that clamps to DNA - ANS✅✅Beta
Subunits of DNA pol III that load enzyme on template - ANS✅✅Gamma, Delta prime, Delta, X, Phi
Subunit of DNA pol lll that dimerizes core complex - ANS✅✅Tao
Theta subunit of DNA pol III is involved in - ANS✅✅core assembly
Helicase - ANS✅✅Unwind and cuts DNA ds using hydrolysis of ATP to break H bonds.
, Single strand binding proteins - ANS✅✅Prevents ssDNA from going wild
Topoisomerases (DNA gyrase) - ANS✅✅Stops molecule from being over twisted or under twisted.
Unwinding produces supercoiling that is relieved via DNA gyrase.
RNA Primase - ANS✅✅Adds primer to DNA strand so DNA polymerase can bind to 3' OH and start
replicating. Synthesizes 5'->3'
DNA ligase - ANS✅✅A linking enzyme essential for DNA replication; catalyzes the covalent bonding
of the 3' end of a new DNA fragment to the 5' end of a growing chain by forming a phosphodiester
bond.
oriC - ANS✅✅Origin of replication in procaryotes. Unique base pair sequence that define a region
and are recognized by proteins. DNA becomes denatured from proteins/enzymes replication begins.
DNAa - ANS✅✅Binds to 9mers causing kink in DNA which distorts the helix leading to the
formation of a replication bubble.
DNAB/DNAC - ANS✅✅Once replication bubble is formed DNAB/DNAC initiate helical unwinding
Are AT or GC bonds easier to disrupt? - ANS✅✅AT binds are weaker because they have 2 H bonds
while GC pairing involves 3 H bonds.
How many oriC's do prokaryotes/Eukaryotes have? - ANS✅✅Prokaryotes have one oriC per
chromisome. Eukaryotes have multiple. (Maybe because prokaryotic genome is cyclical?)
Leading strand - ANS✅✅Continuous 5'->3' synthesis.
Lagging strand - ANS✅✅Discontinusous 5'->3' synthesis via formation of Okazaki fragments.
How does DNA pol III synthesize two strands of DNA in opposite directions? - ANS✅✅It makes a
hairpin in the DNA causing both strands to be synthesize in the same direction spatially but not
chemically/structurally/physically/actually. The size of the Okazaki fragments depends on the size of
the hairpin.
answers graded A+
What are the 4 components required for DNA synthesis? - ANS✅✅dNTPs (A,G,C,T), DNA template
strand and primer, DNA polymerase, Mg 2+ (optimizes DNA polymerase activity)
Which direction does DNA synthesize? - ANS✅✅5'->3'
DNA POL 1 - ANS✅✅Catalyzes formation of phosphodiester bond between the last and incoming
nucleotides. Degrades RNA primer via 5'->3' exonuclease.
The energy used by DNA POL 1 is derived from... - ANS✅✅the release of two of the three
phosphates of the dNTP.
Which DNA polymerase has 5'-3' polymerase activity? - ANS✅✅I, II, III
Which DNA polymerase has 3'->5' (exonuclease) error correction/ proof reading activity? -
ANS✅✅I, II, III, IV, V
3'->5' exonuclease subunit of DNA pol III - ANS✅✅Epsilon
Polymerase subunit of DNA pol III - ANS✅✅Alpha
Subunit of DNA pol III that clamps to DNA - ANS✅✅Beta
Subunits of DNA pol III that load enzyme on template - ANS✅✅Gamma, Delta prime, Delta, X, Phi
Subunit of DNA pol lll that dimerizes core complex - ANS✅✅Tao
Theta subunit of DNA pol III is involved in - ANS✅✅core assembly
Helicase - ANS✅✅Unwind and cuts DNA ds using hydrolysis of ATP to break H bonds.
, Single strand binding proteins - ANS✅✅Prevents ssDNA from going wild
Topoisomerases (DNA gyrase) - ANS✅✅Stops molecule from being over twisted or under twisted.
Unwinding produces supercoiling that is relieved via DNA gyrase.
RNA Primase - ANS✅✅Adds primer to DNA strand so DNA polymerase can bind to 3' OH and start
replicating. Synthesizes 5'->3'
DNA ligase - ANS✅✅A linking enzyme essential for DNA replication; catalyzes the covalent bonding
of the 3' end of a new DNA fragment to the 5' end of a growing chain by forming a phosphodiester
bond.
oriC - ANS✅✅Origin of replication in procaryotes. Unique base pair sequence that define a region
and are recognized by proteins. DNA becomes denatured from proteins/enzymes replication begins.
DNAa - ANS✅✅Binds to 9mers causing kink in DNA which distorts the helix leading to the
formation of a replication bubble.
DNAB/DNAC - ANS✅✅Once replication bubble is formed DNAB/DNAC initiate helical unwinding
Are AT or GC bonds easier to disrupt? - ANS✅✅AT binds are weaker because they have 2 H bonds
while GC pairing involves 3 H bonds.
How many oriC's do prokaryotes/Eukaryotes have? - ANS✅✅Prokaryotes have one oriC per
chromisome. Eukaryotes have multiple. (Maybe because prokaryotic genome is cyclical?)
Leading strand - ANS✅✅Continuous 5'->3' synthesis.
Lagging strand - ANS✅✅Discontinusous 5'->3' synthesis via formation of Okazaki fragments.
How does DNA pol III synthesize two strands of DNA in opposite directions? - ANS✅✅It makes a
hairpin in the DNA causing both strands to be synthesize in the same direction spatially but not
chemically/structurally/physically/actually. The size of the Okazaki fragments depends on the size of
the hairpin.
