Discuss the roles of abiotic and biotic factors in determining species richness, drawing on examples from four ecosystems.

Biotic factors are living things within an ecosystem; such as plants, animals, and bacteria, while abiotic are non-living components; such as water, soil and atmosphere.

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

c: warm water flows from the western tropical pacific toward south america. that should be the right answer! hope it .