D, because both A and C are correct.
Producers provide oxygen gas as a result from photosynthesis - something that almost all other organisms at high trophic levels need
Answer:
Biofuels have been around longer than cars have, but cheap gasoline and diesel have long kept them on the fringe. Spikes in oil prices, and now global efforts to stave off the worst effects of climate change, have lent new urgency to the search for clean, renewable fuels.
Our road travel, flights, and shipping account for nearly a quarter of the world's greenhouse gas emissions, and transportation today remains heavily dependent on fossil fuels. The idea behind biofuel is to replace traditional fuels with those made from plant material or other feedstocks that are renewable.
But the concept of using farmland to produce fuel instead of food comes with its own challenges, and solutions that rely on waste or other feedstocks haven't yet been able to compete on price and scale with conventional fuels. Global biofuel output needs to triple by 2030 in order to meet the International Energy Agency's targets for sustainable growth.
The Hidden Costs of Turning Food Into Fuel
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THE HIDDEN COSTS OF TURNING FOOD INTO FUEL
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Explanation:
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 think it's D. Sry if you get it wrong though
