Why is the citric acid cycle a cyclic pathway rather than a linear pathway?
in the oxidation of pyruvate to acetyl coa, one carbon atom is released as co₂. however, the oxidation of the remaining two carbon atoms—in acetate—to co₂ requires a complex, eight-step pathway—the citric acid cycle. consider four possible explanations for why the last two carbons in acetate are converted to co₂ in a complex cyclic pathway rather than through a simple, linear reaction.

sheep is a herbivore animal whereas grasshopper belongs to the class chordates but both of them feed on greens.  

if grasshopper and sheep feeding on a pasture land, i do not think both of them will have any impact on each other. however, the number of the species can make difference. since sheep feed on greens, there is a possibility there left no pasture land for the grasshoppers or they may get extinct.

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.