Why can it be difficult to define the boundaries of an ecosystem?

"acknowledging a right to benefit from the presence of animals requires government action to ensure human access to animals in a number of different spheres," writes jessica pierce, ph.d., in psychology today. the pragmatic meaning of the term "right" in this statement is

The fruit of a certain plant is sweet and fleshy. the seeds of this plant have a seed coat that is fairly tough. the seeds germinate better if they are exposed to acid, or scarification. what is the most likely type of dispersal for this seed? water animal wind

The human body needs energy in order to carry out life processes such as breathing. where does the body get this energy? a. from eating food b. from learning about new things c. from lying in the sun d. from sleeping