Question

RNA synthesis is controlled by
A. Rho factor
B. Sigma factor
C. Endonuclease
D. RNA polymerase

Answer 1

Hint: RNA is ribonucleic acid which is encoded by DNA and itself codes for proteins and, RNA synthesis is a tightly controlled enzymatic process.

Complete answer: RNA is ribonucleic acid and is coded by DNA inside the nucleus in eukaryotes while in prokaryotes it takes place in the cytoplasm. Transcription is the formation of RNA using a DNA template. For transcription, certain enzymes and factors are necessary, out of which RNA polymerase plays an important role.
 

RNA polymerase is also known as DNA-dependent-RNA-polymerase is the main enzyme responsible for RNA synthesis using the DNA template. It is one of the universal enzymes found in prokaryotes, eukaryotes and many viruses as well. RNA polymerase employs a helicase enzyme to unwind the DNA double helix and expose the DNA sequence. Certain transcription factors are employed for initiation, elongation and termination of this process. RNA polymerase is essentially important for RNA synthesis or translation. It is the enzyme that certainly controls RNA synthesis.
So, the correct option is option D.

Note: RNA polymerase is a protein enzyme used for RNA synthesis. RNA can be of multiple types like the mRNA or messenger RNA, tRNA or transfer RNA, rRNA or ribosomal RNA and miRNA or micro RNA. These differ in their work like the mRNA is important for protein synthesis and forms the template for the same. tRNA is also required in translation, it helps in incorporating the amino acid in the protein chain while reading the codon code. rRNA is required for catalysis of protein synthesis, it provides the pocket for the reaction to occur.