What observation led researchers to propose that chloroplasts evolved from cyanobacteria? a) both produce proteins. b) both contain mitochondria. c) both provide structure to cells. d) both perform photosynthesis.

because the light is a great source of energy for the plants to survive. (i hope this )

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.