4. A very large molecule consisting of many smaller structural units linked together Chemical reaction
Macromolecule
Carbohydrate
Nucleic acid
Lipid
Protein

19. scientists use meteorites that hit earth to provide evidence of the composition of earth's interior because they hypothesize that

If the coding part of an mrna molecule is 1800 nucleotides (bases) in length, this molecule will contain codons and code for a polypeptide that is amino acids long.

When analyzing tree rings, what do scientists assume a thin ring indicates?