A cell typically has enough available ATP to meet its needs for about 30 seconds. So what happens in an athlete’s in cell when it exhausts its ATP supply? a) She has to sit down and rest. b) Metabolic processes are activated that generate ATP. c) ATP is transported into the cell from circulation. d) Other cells take over and the muscle cell that has used up its ATP quits. In humans, cardiac muscle is stimulated to increase contraction rate by ? ____ nerves: a) somatic b) cerebellum c) sympathetic d) para sympathetic What is the source of carbon in photosynthesis? a) pyruvate b) isoprene c) carbon dioxide d) glucose e) formaldehyde In protostomes deuterostomes, the space between the endoderm and the ectoderm is important because: a) it provides a perfect environment that can be maintained for all the cells even if the outside environment change b) protostomes use their ectoderm to develop digestive organs inside it c) deuterostomes develop their brain from the mesoderm in this space d) the endoderm form the immune system in this space, e) all are important.