you've made the hypothesis that the higher the density of a rock, the higher the temperature at which it will melt, because a denser rock contains more material.
what is one thing that you should control in an experiment designed to test this hypothesis?
a. the color of each rock
b. the weight of each rock
c. the density of each rock
d. the temperature at which each rock melts

C. The density of each rock

examples of nucleic acids are deoxyribonucleic acid (dna) and ribonucleic acid (rna).

the nitrogen cycle provides nitrogen to the ecosystem from the atmosphere, ground and oceans. nitrogen is an important component of complex molecules such as amino acids and nucleotides, which lead to the creation of proteins and dna, the building blocks of all life. plants absorb nitrogen in the form of ammonium, nitrate ion and, on rare occasions, as amino acids. animals receive nitrogen necessary for biological processes from feeding on living or dead organic matter.