GENETICS AND EVOLUTION
MOLECULAR BASIS OF INHERITANCE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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DNA polymerase I
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DNA polymerase III
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helicase
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topoisomerase
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Detailed explanation-1: -Answer and Explanation: DNA polymerase catalyzes the elongation of a DNA strand in the 5’-3’ direction.
Detailed explanation-2: -DNA polymerase III holoenzyme (Pol III HE) is an enzyme that catalyzes elongation of DNA chains during bacterial chromosomal DNA replication.
Detailed explanation-3: -coli, which enzyme catalyzes the elongation of a new DNA strand in the 5’ → 3’ direction? DNA polymerase can join new nucleotides only to the 3 end of a pre-existing strand, and the strands are antiparallel.
Detailed explanation-4: -Taq DNA polymerase has a domain at its amino terminus (residue 1 to 291) that has a 5’-3’ exonuclease activity, a 3’-5’ exonuclease domain in the middle (residue 292 to 423), and a domain at its C-terminus that catalyzes polymerase reactions.
Detailed explanation-5: -DNA is always synthesized in the 5’-to-3’ direction, meaning that nucleotides are added only to the 3’ end of the growing strand. As shown in Figure 2, the 5’-phosphate group of the new nucleotide binds to the 3’-OH group of the last nucleotide of the growing strand.