Which material will students use in all three models?

D. Nucleus

Explanation:

Prokaryotes are unicellular organisms that lack membrane-bound structures, the most noteworthy of which is the nucleus.

Like a prokaryotic cell, a eukaryotic cell has a plasma membrane, cytoplasm, and ribosomes. ... a membrane-bound nucleus.

All viruses contain nucleic acid, either DNA or RNA (but not both), and a protein coat, which encases the nucleic acid.

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."

answer: 20 percent

the fish culture has become a developing commercial practice in developing countries which is already prominent in developed countries of the world. the major fish protein demand is being supplemented in developing countries is   fishing to meet the needs of the growing population. therefore, in some developing nations, the percentage of animal protein from fish in the diet can be as high as 20 percent.