The nutrient content and oxygen levels in streams and rivers often change from one part to another. Drag and drop the tiles to match the relative oxygen levels and zones of the river to its corresponding nutrient levels. Also, place the picture of an organism that would most likely inhabit each zone.

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.