How does carbon enter biotic (living) part of ecosystem, namely plants from the atmosphere?

One function of the poly-a tail on eukaryotic mrna sequences is to the mrna be transported from the nucleus to the cytoplasm. prokaryotic mrna also has a poly-a tail. choose the best explanation of the prokaryotic poly-a tail. a. prokaryotic poly-a tails have the same functions as eukaryotic poly-a tails, because this process is highly conserved throughout different species. b. prokaryotic poly-a tails aren't important, because prokaryotes don't have nuclei. c. prokaryotic poly-a tails have other functions, because prokaryotes don't have nuclei. d. prokaryotic poly-a tails are composed of a different molecular structure compared with eukaryotic poly-a tails.

If scientists are wrong about earth's age based on radioactive material and the decay rates are really much faster, how would nuclear power plants be affected?

The circles, or orbits, for electrons are called energy levels. each level can hold only a certain number of electrons. add electrons to each level until you can't add any more. how many electrons can each level hold?