UW Madison Bio 151 Exam 2
Questions and All Correct Answers
2025-2026 Updated.
x-ray crystallography - Answer makes DNA crystal, shines X-rays to form a scatter pattern that
gives information about the structure of DNA
double helix structure - Answer describes two interlinked strands of DNA making a spiraling
"ladder"
DNA strand - Answer a single series of nucleotide bases covalently linked in any order
dNTPs - Answer deoxynucleotide triphosphates
sugar-phosphate backbone - Answer an alternating chain of sugars (ribose or deoxyribose) and
phosphates that make up the outside of the DNA or RNA
phosphodiester bond - Answer
antiparallel - Answer opposite arrangement of helix strands -- parallel in opposite directions
5' end of DNA - Answer one end of a DNA chain, refers to a sugar with a 5' phosphate group
attached to it
3' end of DNA - Answer one end of a DNA chain. refers to a sugar with a 3' hydroxyl attached
to it
complementary/matching base bairs - Answer A and T (or U in RNA), C and G
semi-conservative - Answer the process of replicating DNA "conserves" one template strand
and makes one new strand
DNA polymerase - Answer enzyme that matches complementary nucleotides with the
, single strand binding proteins - Answer proteins that stabilize the single strands of DNA to
prevent them from re-binding to one another
origin of replication - Answer specific DNA sequence where helicases and polymerase begin
the replication process
replication bubble - Answer region of DNA between the two "unzipped" strands, where the
origin of replication is
replication fork - Answer y-shape created by unzipped sections of DNA
supercoiling - Answer phenomena that occurs as the DNA strands are unwound where the
still-wound pieces tighten increasingly
topoisomerase - Answer enzyme that prevents supercoiling by cutting the strands and
allowing them to unwind and then re attaching them
primase - Answer enzyme that makes the RNA primer
RNA primer - Answer indicates where the RNA polymerase should start replicating the DNA
DNA ligase - Answer enzyme that links the two replicated NDA fragments
leading strand - Answer strand of DNA being replicated continuously - "bottom" strand of
replicated DNA
lagging strand - Answer strand of DNA being replicated DIScontinously - "top" strand of
replicated DNA
okazaki fragment - Answer short segments of DNA synthesized in the lagging strand during
DNA replication
telomere - Answer the end of a linear chromosome that contains a repeated sequence of DNA
Questions and All Correct Answers
2025-2026 Updated.
x-ray crystallography - Answer makes DNA crystal, shines X-rays to form a scatter pattern that
gives information about the structure of DNA
double helix structure - Answer describes two interlinked strands of DNA making a spiraling
"ladder"
DNA strand - Answer a single series of nucleotide bases covalently linked in any order
dNTPs - Answer deoxynucleotide triphosphates
sugar-phosphate backbone - Answer an alternating chain of sugars (ribose or deoxyribose) and
phosphates that make up the outside of the DNA or RNA
phosphodiester bond - Answer
antiparallel - Answer opposite arrangement of helix strands -- parallel in opposite directions
5' end of DNA - Answer one end of a DNA chain, refers to a sugar with a 5' phosphate group
attached to it
3' end of DNA - Answer one end of a DNA chain. refers to a sugar with a 3' hydroxyl attached
to it
complementary/matching base bairs - Answer A and T (or U in RNA), C and G
semi-conservative - Answer the process of replicating DNA "conserves" one template strand
and makes one new strand
DNA polymerase - Answer enzyme that matches complementary nucleotides with the
, single strand binding proteins - Answer proteins that stabilize the single strands of DNA to
prevent them from re-binding to one another
origin of replication - Answer specific DNA sequence where helicases and polymerase begin
the replication process
replication bubble - Answer region of DNA between the two "unzipped" strands, where the
origin of replication is
replication fork - Answer y-shape created by unzipped sections of DNA
supercoiling - Answer phenomena that occurs as the DNA strands are unwound where the
still-wound pieces tighten increasingly
topoisomerase - Answer enzyme that prevents supercoiling by cutting the strands and
allowing them to unwind and then re attaching them
primase - Answer enzyme that makes the RNA primer
RNA primer - Answer indicates where the RNA polymerase should start replicating the DNA
DNA ligase - Answer enzyme that links the two replicated NDA fragments
leading strand - Answer strand of DNA being replicated continuously - "bottom" strand of
replicated DNA
lagging strand - Answer strand of DNA being replicated DIScontinously - "top" strand of
replicated DNA
okazaki fragment - Answer short segments of DNA synthesized in the lagging strand during
DNA replication
telomere - Answer the end of a linear chromosome that contains a repeated sequence of DNA
