Ribonucleotide reductase regulates the rate of DNA synthesis and the total  DNA to cell mass ratio. The enzyme converts adenosine diphosphate (ADP), guanosine diphosphate (GDP), cytidine diphosphate (CDP), uridine diphosphate (UDP). The ribonucleotide thymidine diphosphate is not a substrate for this enzyme. Thymidine nucleotides are products of another enzyme: thymidylate kinase.

Purines can be synthesized de novo from ribose phosphate. 5-phosphoribosylamine is converted to inosine monophosphate, which is an intermediary for adenine monophosphate and guanine monophosphate production. The reaction requires the presence of glycine, aspartate and glutamine, but not lysine.

Phosphoribosyl pyrophosphate (PRPP) is a precursor of both purines (adenine and guanine), as well as pyrimidines (cytosine, uracil, and thymine) in nucleotide synthesis. In certain enzyme deficiencies, levels of PRPP can increase leading indirectly to uric acid production and gout.

Nucleases are important in excision of  nucleotides from the DNA chain. Phosphodiester bonds between two nucleotides are broken and the DNA chain becomes fragmented. Site-specific nucleases can function as restriction enzymes cutting phosphodiester bonds at specific locations inside the DNA molecule. In DNA repair they remove nucleotides incorrectly placed during DNA synthesis.

DnaA protein in bacteria binds to a base pair sequence at the origin of replication serving as an initiation factor for DNA synthesis. All the other answers are wrong as: helicase, not DnaA protein unwinds DNA; single-stranded DNA binding protein stabilizes separated DNA strands; primase synthesizes RNA primers; and DNA polymerase I replaces RNA with DNA.

Because the lagging strand is created in various separate segments during DNA replication, after polymerization they must be joined together by an enzyme. The enzyme that is responsible for these connections is DNA ligase.

Topoisomerase I functions as a stress reliever during DNA replication. DNA coils and supercoils, and without topoisomerase, the tension caused by this winding would not be able to dissipate.  

The correct matches between prokaryotic DNA polymerase type and function are:

DNA polymerase I - fills in gaps in lagging strand

DNA polymerase II - DNA repair

DNA polymerase III - primary enzyme for DNA synthesis

Note: The functions of certain DNA polymerases in eukaryotes and prokaryotes are not the same.

Transcription is the second process involved in the production of proteins from a gene. The three processes are DNA replication, transcription, and translation. DNA replication involves replication of DNA from a parent strand, transcription involves the synthesis of a RNA molecule from a DNA molecule, and translation involves the conversion of the mRNA molecule to a polypeptide.

As mentioned, transcription produces an RNA molecule from a DNA molecule (parent strand). Recall that RNA molecules have uracil, whereas DNA molecules have thymine; therefore, the product will contain more uracil.

Amino acids are found in proteins. Since the products of transcription are nucleic acids (RNA molecules) they won’t contain any amino acids. Recall that a nucleic acid consists of pentose sugar molecules (ribose in RNA and deoxyribose in DNA), nitrogenous bases (adenine, guanine, cytosine, thymine (in DNA), and uracil (in RNA)), and phosphate groups.

RNA polymerase is an important enzyme involved in transcription. Its function is to add nucleotides to the growing mRNA chain. Although it adds complementary nucleotides to the DNA, RNA polymerase itself doesn’t bind to complementary DNA sequences, rather it binds at promoters.

There are three types of RNA molecules. First, mRNA molecules are the main products of transcription that undergo translation to produce most of the proteins found in a cell. Second, tRNA molecules are special RNA molecules that facilitate the addition of amino acids to a growing polypeptide chain during translation. Third, rRNA molecules are components of ribosomes and are synthesized in the nucleolus (location of assembly of ribosomes). The enzyme in this question is involved in the production of rRNA molecules. RNA polymerase I is used in production of rRNA molecules. RNA polymerase II is used for mRNA molecules and RNA polymerase III is used for tRNA molecules.