DNA molecules are composed of four nucleotides, and these nucleotides are linked together much like the words in a sentence. Together, all of the DNA "sentences" within a cell contain the instructions for building the proteins and other molecules that the cell needs to carry out its daily work.
Explanation:
A strand of DNA is much like an extremely long sentence that uses only four letters. DNA actually has two strands, much like a zipper and the nucleotides are like the teeth of that zipper. This two-strand system is the key to how DNA is able to make copies of itself.
Relative and average atomic mass both describe properties of an element related to its different isotopes.
Explanation:However, relative atomic mass is a standardized number that's assumed to be correct under most circumstances, while average atomic mass is only true for a specific sample.