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.
I believe they are called endothermic.
Endotherms also called warm blooded animals are those that maintain a constant body temperature independent of the environment. They primarily includes, birds and animals, but some fish are also endothermic. On the other hand ectothermic animals or cold blooded animals are those whose regulation of body temperature depends on the external sources such as sunlight.
It is important to know the division or phylum of the various plant species growing in your backyard so as to determine whether they will spread and ruin other crops and plants of yours. Not every plant is beneficial, so you need to know which ones to keep, and which to deplant.