Which has the greatest effect on the amount of salt in a salt marsh? A) the number of animals living in the marsh
B) the closeness of the marsh to the ocean
C) the depth of the water in the marsh
D) the temperature of the water in the marsh

the correct answer is:

a population changes in response to a change in the environment.

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