Which of these statements are true and which are false? 1. plants respire only during the night. 2.plants break down glucose and use it for metabolism. 3.energy is released during the process of respiration. 4.respiration is limited to human beings and animals. 5.animals cannot use carbon dioxide from the atmosphere. they utilize only oxygen. 6.the products of photosynthesis are the reactants of respiration. 7.plants do not need oxygen. they need only carbon dioxide. 8.water is used up in respiration, whereas it is given out as a by-product in photosynthesis.