THE MOLECULAR BASIS OF INHERITANCE
DNA REPLICATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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breaks and rejoins the DNA double helix to relieve twisting forces caused by the opening of the helix
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catalyzes the joining of Okazaki fragments into a continuous strand
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removes the RNA primer and replaces it with DNA
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catalyzes the synthesis fo the RNA primer on an Okazaki fragment, and provides a starting point of RNA or DNA polymerase to begin synthesis of new strand
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Detailed explanation-1: -Primase: synthesize the RNA primers required for initiating leading and lagging strand synthesis.
Detailed explanation-2: -These primases synthesize a primer RNA once on each leading strand template to initiation DNA synthesis and repeatedly on the lagging strand template to initiate Okazaki fragment synthesis. Primase initiate synthesis from specific trinucleotides that differ according to the organism’s phylogeny.
Detailed explanation-3: -These primers serve as a starting point for DNA synthesis. Since primase produces RNA molecules, the enzyme is a type of RNA polymerase. Primase functions by synthesizing short RNA sequences that are complementary to a single-stranded piece of DNA, which serves as its template.
Detailed explanation-4: -Because of its 5′ to 3′ exonuclease activity, DNA polymerase I removes RNA primers and fills the gaps between Okazaki fragments with DNA.