Over Time,dissolved Magnesium Concentration in a Lake Has Reached Equilibrium

question 7

Multiple Choice

Over time,dissolved magnesium concentration in a lake has reached equilibrium.Input is from streams draining into the lake; magnesium is removed by precipitation in lake sediments.If wastewater discharge upstream doubles the rate at which magnesium is delivered to the lake,

• A) The BOD of the lake will double.
• B) The BOD of the lake will be cut in half.
• C) The residence time of magnesium in the lake will double.
• D) The residence time of magnesium in the lake will be halved.

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Definitions:

Pinocytosis

A form of endocytosis in which cells engulf and internalize fluid along with dissolved substances.

Vesicles

Small membrane-bound sacs in cells used for the transport, storage, and digestion of substances.

Electron Microscope

A type of microscope that uses a beam of electrons to create an image of the specimen with much higher resolution than a light microscope.

Selectively Permeable Membrane

A membrane that allows certain molecules or ions to pass through it by diffusion and occasionally specialized processes, crucial in maintaining the cell environment.