What is the maximum concentration of salt in water for an ecosystem to be classified as a freshwater system

Mario performed an experiment to determine if photosynthesis was affected by the amount of light that a plant received. what could he have done to increase the validity of his data? reduce the number of plants. remove the 1 hour group. add a 0 hours control. measure the oxygen in liters

Enzymes are proteins that speed up reactions by providing an additional energy source supplying additional molecules for the reaction removing inhibitors that slow down reactions lowering the amount of energy required

Animals such as pronghorn antelope, bison ans badgers dot to the landscape. where are these animals located?