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.
Cell bio is important so that we can know more about cells and how they function
Answer:
B. The sugar dissolves in the water and the lemon slices do not.
Explanation:
The lemons floated to the top of the glass and the sugar dissolved. Only the sugar is soluble
the correct answer is A- Reproductive isolation occurred through behavioral isolation
A process of formation of a new species from an existing species is called speciation. New species may formed due to geographical or reproductive barriers which isolates the members of a population of a species to form a new species.
In the given question, speciation in In the leopard frogs occurred due to a particular or specific call given by males to the females. The courtship call lead to reproductive isolation due to change in behavior. Such type of behavioral change will help in recognizing mates of the same species and this will act as a reproductive barrier among the other related species.