GENETICS AND EVOLUTION
MOLECULAR BASIS OF INHERITANCE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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DNA molecule being synthesised is very long
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DNA dependent DNA polymearse catalyses polymerisation only in one direction (5’
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it is a more efficient process
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DNA ligase has to have a role
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Detailed explanation-1: -The correct answer is C) DNA-dependent DNA polymerase catalyses polymerisation only in one direction (5′ to 3′). DNA-dependent DNA polymerase catalyses polymerisation only in one direction (5′ to 3′). This produces extra complications at the replication fork.
Detailed explanation-2: -Discontinuous DNA synthesis occurs in the 5’ 3’ direction on the parent strand. This strand is often referred to as the lagging strand. It is completed in short sequences of nucleotides called Okazaki fragments. Replication on the lagging strand begins with the addition of an RNA primer by the enzyme primase.
Detailed explanation-3: -On the upper lagging strand, synthesis is discontinuous, since new RNA primers must be added as opening of the replication fork continues to expose new template. This produces a series of disconnected Okazaki fragments.
Detailed explanation-4: -Lagging-strand replication is discontinuous, with short Okazaki fragments being formed and later linked together.