Answer : Photosynthesis is an example of a chemical reaction.
Explanation :
Photosynthesis : It is a type of chemical process which takes place in the plant cell. In photosynthesis process, the light energy converted into the chemical energy.
As plant needs carbon dioxide, water and light. During the photosynthesis, carbon dioxide, water and sunlight react to gives glucose, oxygen and water as a product.
The balanced reaction of photosynthesis will be,

Hence, photosynthesis is an example of a chemical reaction.
Haikyuu is thehonest so D I guess
Answer:
Black fur is more fit to survive in the environment than other colors of fur.
Explanation:
"Fitness", in terms of natural selection, is an organism's likelihood to survive in a given environment. Assuming that the increase in black fur is significant (Not attributable to pure chance), we can safely assume this is because Black Fur provides a competitive advantage in said environment over other colors of fur. There may be black terrain that allows them to blend into the environment and ovoid predators, or maybe it keeps them warmer if it is located in a cold region, thereby reducing the amount of resources they need to spend to stay warm.
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.