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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Helicase unwinds the parent strand of DNA
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DNA polymerase synthesizes template DNA from the parent strand
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DNA is synthesized in the 5’ to 3’ direction
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DNA ligase joins Okazaki fragments together
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Detailed explanation-1: -Which of the following represents a step necessary to create the lagging strand, but not the leading strand, during DNA replication? Explanation: Okazaki fragments are only produced, and subsequently joined together, in the lagging strand to allow for replication in the opposite direction as replication fork movement.
Detailed explanation-2: -Here, an enzyme called ligase comes in and removes the primers needed for both the leading and lagging strands and replaces them with DNA nucleotides.
Detailed explanation-3: -Which is involved in replicating the lagging strand of DNA, but is not involved in leading strand replication? Ribosome.
Detailed explanation-4: -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-5: -The lagging strand begins replication by binding with multiple primers. Each primer is only several bases apart. DNA polymerase then adds pieces of DNA, called Okazaki fragments, to the strand between primers. This process of replication is discontinuous as the newly created fragments are disjointed.