PATHOLOGY MCQ
CELL DAMAGE
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Separating the two strands of the double helices
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Preventing double helices from over-winding and breaking by relieving tension
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Adding primers to template parent strands
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Synthesizing complementary daughter strands from template parent strands
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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: -Primase is an enzyme that synthesizes short RNA sequences called primers. These primers serve as a starting point for DNA synthesis. Since primase produces RNA molecules, the enzyme is a type of RNA polymerase.
Detailed explanation-3: -DNA primases are enzymes whose continual activity is required at the DNA replication fork. They catalyze the synthesis of short RNA molecules used as primers for DNA polymerases. Primers are synthesized from ribonucleoside triphosphates and are four to fifteen nucleotides long.
Detailed explanation-4: -A primer must be synthesized by an enzyme called primase, which is a type of RNA polymerase, before DNA replication can occur. The synthesis of a primer is necessary because the enzymes that synthesize DNA, which are called DNA polymerases, can only attach new DNA nucleotides to an existing strand of nucleotides.
Detailed explanation-5: -Primer synthesis marks the beginning of the actual synthesis of the new DNA molecule. Primers are short stretches of nucleotides (about 10 to 12 bases in length) synthesized by an RNA polymerase enzyme called primase.