in this forest, trees block much of the sunlight from reaching the ground. the branches of trees grow up and out to reach as much sunlight as they can. which challenge of life does this example represent? a) obtaining energy b) needing sleep c) reproducing d) maintaining structure

answer: accepted answer: aquatic animals use the oxygen dissolved in water to carry out respiration. since the amount of dissolved oxygen in water is low as compared to the amount of oxygen in the air, therefore the rate of breathing in aquatic animals is much faster than it is in terrestrial animals.

explanation: