TFIIE -80 to +30 For bacterial RNA polymerase, only the sigma factor is needed for the enzyme to recognize the promoter. The eukaryotic transcription factors may indeed act as sigma factors to allow the eukaryoitic RNA polymerase to recognize the promoter.
An energy pyramid is the graphical representation of the trophic levels (nutritional) by which the incoming solar energy is transferred into an ecosystem.The source of energy for living beings on Earth is the Sun.The energy that the Sun emits at present is of 1366.75 W/m^2 (400 years ago, it was of 1363.48 W/m^2).n energy pyramid is the graphical representation of the trophic levels (nutritional) by which the incoming solar energy is transferred into an ecosystem.
Energy can be considered in two categories - primary and secondary. 1  Primary energy is energy in the form of natural resources, such as wood, coal, oil, natural gas, natural uranium, wind, hydro power, and sunlight. 2  Secondary energy is the more useable forms to which primary energy may be converted, such as electricity and petrol.