Answer:
Sigma factor is the name of the protein and it helps RNA polymerase to recognize promoter.
Explanation:
RNA polymerase is the enzyme which helps in the transcription of DNA duplex. In bacteria, a protein called sigma factor is present in RNA polymerase which is responsible for the initiation of transcription.
The sigma factors gives the ability to RNA polymerase to recognize the promoter sequence. If the sigma factor is not present in RNA polymerase than this enzyme can not distinguish between promotor and other sequences.
So the sigma factor increases the affinity of RNA polymerase towards promoter and helps in initiation of the transcription. Sigma factor gets released from the core enzyme when the chain reaches 8-9 bases.
The correct answer is option D, difficulty of redesigning workable ecosystems
Reason -
The area that was redesigned into an ecosystem actually failed to attract the endangered species of clapper rails in California because of the following two reasons –
a) Failed attempt of restoration of Cord grass ( a tree which is a dominant tree in the nesting habitat of clapper rail) . Even if few such trees were there they could not grow to their full height and thus were incapable of providing adequate nesting cover
b) Due to the lack of predatory insect, some herbivore insect in the ecosystem attacked the green grasses thereby making the nesting inadequate.
Brachiopoda hope this helps :)
There are three large domains: Bacteria, Archaea, and <span>Eukarya. Therefore, the </span>answer is FALSE viruses do not have a domain.