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.
A biomass pyramid shows the total mass of the organisms that each trophic level occupies in an ecosystem. Usually, producers have a higher biomass than any other trophic level, but there can be lower amounts of biomass at the bottom of the pyramid if the rate of primary production per unit biomass is very fast.n energy pyramid is a presentation of the trophic levels in an ecosystem. Energy from the sun is transferred through the ecosystem by passing through various trophic levels. Roughly 10% of the energy is transferred from one trophic level to the next, thus preventing a large amounts of trophic levels.