Umm.. What is the answer then please help

Robert wants to know which fertilizer will work the best for his grass. what can he do to explore this inquiry?

In dna, only the_ varies from one nucleotide to another. base phosphate sugar amino acid

The fish shown above is a tarpon. it is a fast-swimming and powerful open-water fish. its closest relatives, oddly, are burrow-dwelling conger eels that stay on the bottom. both eels and tarpon developed from snake-like larvae that float in the plankton during the first stages of life. once they mature, tarpon and eels are not found near one another in the ocean. the tarpon and the eel illustrate all of the following except