Why are protozoa significant? select all that apply. protozoa contaminate the water supply. protozoa do not contribute to a food chain. some protozoa clean polluted water. some protozoa are parasitic and cause diseases like malaria. protozoa have an important role in the food chain.

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.

the cost of mining is extremely low compared to the money earned from mining, creating income to improve the environment.