What is a non example of a community?

Which direction does the energy flow in this energy pyramid ?

What is the main fuel source for the work of the cell

Dna, in the nucleus carries the genetic code for making proteins in ribosomes. in the diagram, b, represents the proteins produced. dna cannot leave the nucleus to carry the genetic information to the ribosome where proteins are produced. how does the genetic code get from the nucleus to the ribosome? what does a represent? now