The correct option is B 1-(C), 2-(A), 3-(B)
Transcription is the process of copying genetic information from one strand of the DNA (template strand) into RNA.
It occurs in three steps: initiation, elongation and termination.
For initiation of transcription, the sigma factor of RNA polymerase is required and for termination the rho factor encounters RNA polymerase.
RNA polymerase ‘core’ consists of 2-alpha subunits, 1-beta subunit, 1 beta’ subunit, 1 omega subunit.
RNA polymerase ‘core’ and the sigma factor interact to form RNA polymerase ‘holoenzyme’.
Thus, the alpha subunit forms the core enzyme of RNA polymerase.
A sigma factor is a protein needed only for initiation of RNA synthesis in bacteria. It is also called the specificity factor. Sigma factors provide promoter recognition specificity to the RNA polymerase and contribute to DNA strand separation. They then dissociate from the RNA polymerase core enzyme following transcription initiation.
Rho (ρ) is an ATP-dependent RNA-stimulated helicase that disrupts the initial RNA-DNA complex and hence serves as a transcription termination factor.