The earliest (geologically speaking) ceratopsid fossils are found in , but the last, from the end of the Cretaceous are only found in.

nucleic acid molecules are incredibly complex, containing the code that guarantees the four different nucleotide units comprise dna, the nucleic acid of interest to the genealogist. and one of four nitrogen-containing molecules called nucleotides

multiplying and dividing the two decimals and the eqations by the same number of the overalls

all matter is made up of atoms

in any element all atoms are the same

elements in a compound are always in a constant ratio: apex