Answer:
Nucleotides make up DNA, or deoxyribonuleic acid.
Explanation:
The answer may be, Replication, but I am unsure.
Water is a limited natural resource, vital for the expansion and development of, not only our specie, but each individual living organism in the planet. Hence, in a community proper water management is a must in order to make sure that water be maintained and cared for -used wisely. In one research, it is estimated that by 2025 more places will feel water scarcity than decades ago.
The oxygen cycle can be found in all but the geosphere. There's oxygen in the atmosphere, so it has to be there, and the biosphere includes living things, which breathe oxygen, and water (hydrosphere) is made up of partly hydrogen, so there has to be oxygen there as well.