BIO 431 Exam 1 Questions with Correct Answers Latest 2025-2026
DNA pol I - Answers Removes RNA nucleotides of primer from 5' end and replaces them with
DNA nucleotides
DNA pol III - Answers Using parental DNA as a template, main synthesis of new DNA strand by
adding nucleotides to an RNA primer
Helicase - Answers Enzyme that untwists the double helix of DNA at the replication forks.
DNA Gyrase - Answers Enzyme that temporarily breaks the strands of DNA, relieving the tension
caused by unwinding the two strands of the DNA helix
DNA Topoisomerase I - Answers Relaxes negative supercoils
Breaks one strand and rotates the DNA
DNA Topoisomerase II - Answers Cuts phosphodiester backbone and removes supercoiling by
cutting both strands, double topI
Primase - Answers An enzyme that joins RNA nucleotides to make the primer using the parental
DNA strand as a template.
Single Stranded Binding proteins - Answers keep the strands of DNA separate during replication
DNA Sliding Clamp - Answers keep DNA polymerase firmly attached to the template while it is
synthesizing new strands of DNA
PCNA - Answers Eukaryotic version of B-clamp
RNAse H - Answers removes RNA primers in eukaryotes
DNA Ligase - Answers 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.
DNA Pol a - Answers works with primase to make DNA primers required to initiate DNA
synthesis
DNA Pol e - Answers leading strand synthesis
DNA Pol d - Answers lagging strand synthesis
DNA Pol eta - Answers assists when a T-T dimer halts a replication fork
DNA pol zeta - Answers
SUMO - Answers Small Ubiquitin like Modifier, protein that tags things for multiple purposes, not
degradation. Post translation modification
DNA pol I - Answers Removes RNA nucleotides of primer from 5' end and replaces them with
DNA nucleotides
DNA pol III - Answers Using parental DNA as a template, main synthesis of new DNA strand by
adding nucleotides to an RNA primer
Helicase - Answers Enzyme that untwists the double helix of DNA at the replication forks.
DNA Gyrase - Answers Enzyme that temporarily breaks the strands of DNA, relieving the tension
caused by unwinding the two strands of the DNA helix
DNA Topoisomerase I - Answers Relaxes negative supercoils
Breaks one strand and rotates the DNA
DNA Topoisomerase II - Answers Cuts phosphodiester backbone and removes supercoiling by
cutting both strands, double topI
Primase - Answers An enzyme that joins RNA nucleotides to make the primer using the parental
DNA strand as a template.
Single Stranded Binding proteins - Answers keep the strands of DNA separate during replication
DNA Sliding Clamp - Answers keep DNA polymerase firmly attached to the template while it is
synthesizing new strands of DNA
PCNA - Answers Eukaryotic version of B-clamp
RNAse H - Answers removes RNA primers in eukaryotes
DNA Ligase - Answers 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.
DNA Pol a - Answers works with primase to make DNA primers required to initiate DNA
synthesis
DNA Pol e - Answers leading strand synthesis
DNA Pol d - Answers lagging strand synthesis
DNA Pol eta - Answers assists when a T-T dimer halts a replication fork
DNA pol zeta - Answers
SUMO - Answers Small Ubiquitin like Modifier, protein that tags things for multiple purposes, not
degradation. Post translation modification
