Astudent designs an experiment to determine the effect of sunlight on plant growth. he or she places three identical plants on three different window sills, which permit different amounts of sunlight exposure. each plant receives the same amount of water each day. what is the responding variable in this experiment? a. plant growth b. amount of sunlight c. amount of water d. type of plant

Even though the ostrich is a flightless bird, ostriches still possess wings that stretch approximately two meters across when fully extended. scientists speculate that when dinosaurs became extinct, some of the birds that lived during that time became land dwellers since they were able to consume the food that the dinosaurs once ate. over time, these species grew larger and heavier. eventually, the ostrich species became too big to fly. the wings found on ostriches are known as a. analogous structures. b. homologous structures. c. vestigial structures. d. symmetrical structures.