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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DNA Helicase unwinds original DNA strand
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RNA Primase lays down RNA primer for new nucleotide bases.
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DNA polymerase builds new strands by bring in new nucleotide bases.
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Ligase knits together fragments on lagging strand
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Detailed explanation-1: -Lagging strand synthesis requires (1) protection of the single-stranded DNA (ssDNA) as it is extruded by the helicase, (2) multiple initiation events by a primase, (3) removal of the RNA primer, (4) ligation of the Okazaki fragments, and (5) transfer of the polymerase from the completed fragment to a new primer.
Detailed explanation-2: -The ligase joins the two fragments of DNA to form a longer strand of DNA by “pasting” them together.
Detailed explanation-3: -On the lagging strand, DNA synthesis restarts many times as the helix unwinds, resulting in many short fragments called “Okazaki fragments.” DNA ligase joins the Okazaki fragments together into a single DNA molecule. Helicase opens up the DNA at the replication fork.
Detailed explanation-4: -DNA ligases are best known for their role in joining adjacent Okazaki fragments at the lagging strand of the replication fork; however, they are essentially involved in any process that requires sealing of phosphodiester bonds from the DNA backbone.