THE MOLECULAR BASIS OF INHERITANCE
DNA MAKES RNA MAKES PROTEIN
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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DNA ligase
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RNA primase
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DNA polymerase I
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DNA helicase
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Detailed explanation-1: -A special mechanism is used to produce the base-paired primer strand required by this DNA polymerase molecule. The mechanism involves an enzyme called DNA primase, which uses ribonucleoside triphosphates to synthesize short RNA primers on the lagging strand (Figure 5-12).
Detailed explanation-2: -The reaction catalyzed by DNA polymerase. All known DNA polymerases add a deoxyribonucleoside 5′-triphosphate to the 3′ hydroxyl group of a growing DNA chain (the primer strand).
Detailed explanation-3: -Primase synthesizes RNA primers complementary to the DNA strand. DNA polymerase III extends the primers, adding on to the 3’ end, to make the bulk of the new DNA.
Detailed explanation-4: -For example, DNA polymerase III does most of the elongation work, adding nucleotides one by one to the 3’ end of the new and growing single strand.
Detailed explanation-5: -PCR (Polymerase Chain Reaction) Because DNA polymerase can add a nucleotide only onto a preexisting 3’-OH group, it needs a primer to which it can add the first nucleotide. This requirement makes it possible to delineate a specific region of template sequence that the researcher wants to amplify.