I think the correct answer from the choices listed above is option C. The purpose of a controlled experiment is to examine whether one variable causes a change in another. A<span>n independent variable is the only factor that is allowed to be adjusted, with the dependent variable as the factor that the independent variable will affect.</span>
changes in the color of the peppered moth population in England
This produces several negative effects on the biodiversity of the river ecosystem.
<u>Explanation:</u>
The Susquehanna river is polluted by the excess release of nutrients like phosphorous and nitrogen from agricultural land and sewage treatment plants. This can adversely affect the health of the river. The excess of nutrients will accelerate the growth of algae in the river.
The dead algae that settle at the bottom of the river decay by consuming the oxygen present in the river. This will reduce the amount of dissolved oxygen in the river and affect aquatic life.
Thick algal growth partially prevents the penetration of sunlight into the water and this affects the growth of submerged plants which are food to the fish.
