Photosynthesis is the process by which plants use the sunlight as a form of energy by converting carbon dioxide to make organic compounds that are necessary for growth.
In the first two stages of photosynthesis, the enzymes of the light-dependent reactions are activated by light and oxidation occurs, yielding oxygen gas and hydrogen ions. The hydrogen ions are used in the electron transport chain and are passed through the thylakoid. The electron transport chain results in the catalyzed reaction of adenosine diphosphate, or ADP, to adenosine triphosphate, or ATP, which is a source of chemical energy.
Later on in the Calvin cycle, the enzymes are important for the production of a three-carbon sugar, then a six-carbon sugar. There are three phases of the cycle that are powered by ATP and nicotinamide adenine dinucleotide phosphate, or NADPH. Being that the Calvin cycle is a metabolic pathway, the carbon compounds produced in the cycle are an important energy source that are used to make organic compounds used by the autotroph.
The correct answer is B. Natural selection occurs through generations and is in which organisms best suited to their environment survive.
