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 polymerase I adds nucleotides in a 5’
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DNA polymerase III adds nucleotides in a 5’
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DNA polymerase I adds nucleotides in a 3’
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DNA polymerase III adds nucleotides in a 3’
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Detailed explanation-1: -The lagging strand is a single DNA strand that, during DNA replication, is replicated in the 5′ – 3′ direction (opposite direction to the replication fork). DNA is added to the lagging strand in discontinuous chunks called ‘okazaki fragments’.
Detailed explanation-2: -Helicase, primase, and two molecules of DNA polymerase III carry out coordinated synthesis of both the leading and lagging strands of DNA.
Detailed explanation-3: -The dimeric structure of the DNA polymerase III holoenzyme couples leading and lagging strand DNA syntheses during replication. Leading strand synthesis (bottom strand) is continuous and processive, but lagging strand synthesis must reinitiate many times during replication of the chromosome.
Detailed explanation-4: -Leading and lagging strands One new strand, the leading strand, runs 5’ to 3’ towards the fork and is made continuously. The other, the lagging strand, runs 5’ to 3’ away from the fork and is made in small pieces called Okazaki fragments.