The answer is A. Oligotrophic lakes are clear and hence
have little vegetation in them (hence no net primary production) that
could initiate the process of eutrophication. Eutrophication is brought about when bacteria
break down the high amount of organic matter hence reduce the oxygen supply in
the waters.
During these initial reactions, water is used and oxygen is released. The energy from sunlight is converted into a small amount of ATP and an energy carrier called NADPH. Together with carbon dioxide, these are used to make glucose (sugar) through a process called the Calvin Cycle.
A non scientific question is a question which cannot be proved to be true as no experiment or no data can be gathered from it. Why are roses the best flowers? is an example of nonscientific question. The answer of this question is subjective and it brings no scientific data. Scientific question on the other hand is a question that may lead to a hypothesis and help us in answering (or figuring out) the reason for some observation.
Tissues form when many similar specializes cells come together.
The level of complexity in organisms from smaller to larger are:
Cells, tissue, organ, organ system, and organism finally.
Cells makes up tissue, tissue makes up organ, organs makes up organ systems, and organ systems makes up an organism.
Therefore, if the same type of cells come together, they'll make up tissue.