Which of the following statements describes what happens to a molecule that functions as the reducing agent in a redox reaction? It gains electrons and gains potential energy. false It loses electrons and loses potential energy. true It gains electrons and loses potential energy.  false It loses electrons and gains potential energy. false Single Which of the following statements correctly describes a distinction between autotrophs and heterotrophs? Cellular respiration is unique to heterotrophs. false Only heterotrophs have mitochondria. false Autotrophs, but not heterotrophs, can nourish themselves, beginning with CO2 and other inorganic nutrients. true Only heterotrophs require oxygen. false Single Which of the following processes is directly associated with photosystem I?  receiving electrons from the thylakoid membrane electron transport chain  true generation of molecular oxygen false extraction of hydrogen electrons from the splitting of water false passing electrons to NADP+ false Single What is the relationship between the wavelength of light and the quantity of energy per photon? They have a direct, linear relationship. false They are inversely related. true They are logarithmically related. false They are separate phenomena. false Single Carotenoids are often found in foods that are considered to have antioxidant properties in human nutrition. What related function do they have in plants? They serve as accessory pigments to increase light absorption. false They protect against oxidative damage from excessive light energy. true They shield the sensitive chromosomes of the plant from harmful ultraviolet radiation.  false They reflect orange light and enhance red light absorption by chlorophyll. false Single In a plant, which of the following reactions produce molecular oxygen (O2)? the light reactions alone true the Calvin cycle alone false the light reactions and the Calvin cycle false neither the light reactions nor the Calvin cycle false Single Where in a plant cell does the Calvin cycle take place?  stroma of the chloroplast true thylakoid membrane false interior of the thylakoid (thylakoid space) false outer membrane of the chloroplast false Single Which of the following processes occurs during the Calvin cycle?  reduction of NADPH false release of oxygen false regeneration of the CO2 acceptor true production of ATP false Single CAM plants keep stomata closed in the daytime, reducing water loss. They can do this because they ________. fix CO2 into organic acids during the night true fix CO2 into sugars in the bundle-sheath cells false fix CO2 into pyruvate in the mesophyll cells false use photosystem I and photosystem II at night  false Single What wavelength of light is most effective in driving photosynthesis? 420 nm true 575 mm false 625 mm false 730 mm false Single