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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Helicases only attach to the leading strand
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the lagging strand is synthesized in separate pieces called Okazaki fragments
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DNA ligase is attached to the leading strand
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Detailed explanation-1: -Each replication fork has a leading and lagging strand, so at each replication bubble there are two leading strands and two lagging strands. The leading strand is synthesized continuously, whereas the lagging strand is synthesized in fragments called Okazaki fragments.
Detailed explanation-2: -Explanation: The lagging strand exists because DNA is antiparallel and replication always occurs in the 5’ to 3’ direction.
Detailed explanation-3: -Due to the antiparallel orientation of the two chromosomal DNA strands, one strand (leading strand) is replicated in a mostly processive manner, while the other (lagging strand) is synthesized in short sections called Okazaki fragments.
Detailed explanation-4: -The leading strand is synthesized in a continuous manner, whereas synthesis of the lagging strand requires a primase that makes RNA primers that are extended by the DNA polymerase to form Okazaki fragments-short DNA fragments that are processed to produce a continuous DNA strand.
Detailed explanation-5: -For the lagging strand, the direction of nucleotide polymerization is opposite to the overall direction of DNA chain growth. Lagging-strand DNA synthesis is delayed because it must wait for the leading strand to expose the template strand on which each Okazaki fragment is synthesized.