Mario sets up an experiment to determine the source of the oxygen gas produced by photosynthesis. To determine this, he uses an
isotope of oxygen called O-18. He labels the O-18 oxygen so he can follow its path through photosynthesis. Plant A is given carbon dioxide that contains the O-18 isotope. Plant B is given water that contains the O-18 isotope. When he examines the oxygen from both plants, only plant B produced O-18 oxygen. What conclusion should he draw about the source of oxygen produced through photosynthesis?
Mario sets up an experiment to determine the source of the oxygen gas produced by photosynthesis. To determine this, he uses an isotope of oxygen called O-18. He labels the O-18 oxygen so he can follow its path through photosynthesis. Plant A is given carbon dioxide that contains the O-18 isotope. Plant B is given water that contains the O-18 isotope. When he examines the oxygen from both plants, only plant B produced O-18 oxygen. This indicates that the source of oxygen is water. The photosynthesis involves the transfer of electrons between the photosystem I and II. The water gets split into oxygen, hydrogen ions and electrons in the photosystem I. The electrons move to the photosystem II where the carbon fixation into sugars takes place. The plant A will have O-18 isotope in its synthesised sugar molecule, which gets stored inside it.
Explanation: Electron microscopes are the most powerful type of microscope, capable of distinguishing even individual atoms. However, these microscopes cannot be used to image living cells because the electrons destroy the samples.
Eating Turkey Won't Make You Sleepy. The oft-repeated turkey myth stems from the fact that turkey contains the amino acid tryptophan, which forms the basis of brain chemicals that make people tired.
