All are part of RNA interference.

siRNA = short interfering RNA

miRNA = micro RNA

pri-miRNA = primary miRNA

piRNA = piwi interacting RNA

Aminoacyl-tRNA synthetases are important enzymes in translation. Their function is to match the specific amino acid to its tRNA. DNA polymerases, RNA polymerase, and DNA helicase are not involved in this process. DNA polymerases are enzymes involved in DNA replication; they create DNA molecules by assembling nucleotides. RNA polymerase produces RNA and has nothing to do with the translation process. Lastly, DNA helicase unwinds DNA during DNA replication, allowing the strands to be copied.

For this question, we're asked to identify an answer choice that contains something that is not needed for transcription and translation.

To begin, let's define these two terms. Transcription is the production of mRNA from DNA. The subsequent coding of a polypeptide from this mRNA is known as translation. During translation, tRNA serves as the carriers of amino acids. In doing so, these tRNA's bring certain amino acids to the ribosome-mRNA complex, depending on the codon sequence of the mRNA. Furthermore, the ribosome itself is composed of rRNA as well as protein. So in total, DNA, mRNA, rRNA, and tRNA are needed for transcription and, subsequently, translation.

But what about miRNA? This type of RNA, together with another class of RNA called siRNA, are both involved in a process called RNA interference. In this process, either miRNA or siRNA acts to inhibit gene expression by inhibiting certain key steps at the level of transcription and translation. Therefore, miRNA is not required for proper transcription and translation to occur because it acts to inhibit these processes.

AUG is the universal start codon. The stop codons are UGA, UAG, and UAA. 

Protein translation begins by recognizing an initiation signal on the mRNA - the codon UAG. The amino acid that coded for by UAG is methionine.

The initiation complex of a ribosome to start translation begins with the tRNA carrying methionine, matching the start codon AUG on mRNA, binding with the 40S and 60S ribosomal subunits, to form an 80S ribosomal subunit with the initiation tRNA in the P site. 

The next tRNA that matches the following codon will then come into the A site to continue translation. 

The monomers from which DNA is polymerized are deoxyribonucleoside triphosphates (dNTPs). When DNA is in its polymerized form, the monomers are deoxyribonucleoside monophospates (dNMPs). This means that each nucleotide that is layed down by DNA polymerase must first have two of its phosphates hydrolyzed (beta and gamma). It is this hydrolysis that drives the nonspontaneous reaction of DNA polymerization.

Prokaryotic DNA replication occurs in the cytoplasm, since these cells lack nuclei. Prokaryotic genomes are comprised of a single circular chromosome, with one origin of replication. Translation is the process of protein synthesis, which occurs on ribosomes free in the cytosol (or on ribosomes embedded in the rough endoplasmic reticulum in eukaryotes).

The only true statement is that prokaryotic DNA replication is faster than eukaryotic DNA replication.

Primase is actually an RNA polymerase, not a DNA polymerase. Primase creates an RNA primer which is used to replicate short-stranded DNA. Primers serve as the starting point for DNA synthesis, so RNA polymerases wouldn’t require them. There are a number of means by which DNA is repaired including direct repair, excision repair, and homologous recombination. DNA repair, however, does not involve the use of RNA polymerases. All rRNA (except 5S rRNA) is synthesized by RNA polymerase I (or to be specific, the polymerase creates a pre-RNA which matures into rRNA), while the precursors of mRNA are synthesized by RNA polymerase II. Primers are short, complementary RNA sequences that serve as the starting point for DNA synthesis; the DNA polymerase begins replication at the primer’s 3’ end, and uses the opposite strand as a template. Without the primer, the DNA polymerase would not have an existing strand of nucleotides onto which it could attach new nucleotides.

To answer this question, it's important to understand that DNA replicates in a semi-conservative fashion. This means that the two complementary strands of DNA split apart, and a new complementary strand is added to each of the parent strands. Thus, each daughter DNA molecule will be composed of one parent strand, and one newly synthesized strand. Since we know that adenine base pairs with thymine, and guanine base pairs with cytosine, the ratio of  is expected to remain the same, provided no mutations occur.