AP BIOLOGY

Detailed explanation-1: -The mechanism involves an enzyme called DNA primase, which uses ribonucleoside triphosphates to synthesize short RNA primers on the lagging strand (Figure 5-12). In eucaryotes, these primers are about 10 nucleotides long and are made at intervals of 100–200 nucleotides on the lagging strand.

Detailed explanation-2: -RNA primase attaches a short RNA molecule called a primer to the DNA sequence, which is removed upon the completion of DNA replication. Another enzyme involved in gene expression is called RNA polymerase, which uses template DNA strands to form RNA molecules.

Detailed explanation-3: -Transcription begins when an enzyme called RNA polymerase attaches to the DNA template strand and begins assembling a new chain of nucleotides to produce a complementary RNA strand.

Detailed explanation-4: -This task is accomplished by an enzyme called a primase, which assembles a short stretch of RNA base-paired to the parental DNA template. This provides a short base-paired region, called the RNA primer, with a free 3’OH group to which DNA polymerase can add the first new DNA nucleotide (Figure 7.12).