AP BIOLOGY

Detailed explanation-1: -During transcription, the DNA of a gene serves as a template for complementary base-pairing, and an enzyme called RNA polymerase II catalyzes the formation of a pre-mRNA molecule, which is then processed to form mature mRNA (Figure 1).

Detailed explanation-2: -Since primase produces RNA molecules, the enzyme is a type of RNA polymerase. Primase functions by synthesizing short RNA sequences that are complementary to a single-stranded piece of DNA, which serves as its template.

Detailed explanation-3: -Because RNA polymerase II is responsible for the synthesis of mRNA from protein-coding genes, it has been the focus of most studies of transcription in eukaryotes.

Detailed explanation-4: -RNA polymerase “core” from E. coli consists of five subunits: two alpha () subunits of 36 kDa, a beta () subunit of 150 kDa, a beta prime subunit (′) of 155 kDa, and a small omega () subunit. A sigma () factor binds to the core, forming the holoenzyme.

Detailed explanation-5: -Messenger RNA (abbreviated mRNA) is a type of single-stranded RNA involved in protein synthesis. mRNA is made from a DNA template during the process of transcription.