In the development of the cell theory, Schleiden and Schwann did not study prokaryotes. Why might this have limited their understanding of cells?

Schleiden and Schwann, in failing to study prokaryotes, would fail to see that there are different types of cells. In doing so, they may give a perception that there are only one type of cell, and that if any other is found, it is "out of the ordinary". Failing to see the differences in the chromosomic pattern can also lead to a failure to identify such cells as cells in the first place. Remember, the two are cells are built differently, and to be able to understand how cells function, all types of known cells must be researched on to gain a clearer picture of the topic of cells.

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

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.