Extract the answer to the question from the following context. Question: What happens at the beginning of fall? Context: In nature, the red color of blood comes from hemoglobin, the iron-containing protein found in the red blood cells of all vertebrates. The red color of the Grand Canyon and other geological features is caused by hematite or red ochre, both forms of iron oxide. It also causes the red color of the planet Mars. The red sky at sunset and sunrise is caused by an optical effect known as Rayleigh scattering, which, when the sun is low or below the horizon, increases the red-wavelength light that reaches the eye. The color of autumn leaves is caused by pigments called anthocyanins, which are produced towards the end of summer, when the green chlorophyll is no longer produced. One to two percent of the human population has red hair; the color is produced by high levels of the reddish pigment pheomelanin (which also accounts for the red color of the lips) and relatively low levels of the dark pigment eumelanin.
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Answer: green chlorophyll is no longer produced

Extract the answer to the question from the following context. Question: What is the highest amount of games a team has played during a season? Context: The practice of playing one or two preseason exhibition games by each team before the start of the regular season was discontinued when the NBC contract was initiated, and the regular season was extended from 14 games, the length that it had been since 1996, to 16 from 2001 to 2010, and since 2016. From 2011 to 2015, the regular season league expanded to 18 games, with each team having two bye weeks and the option of two preseason games.
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Answer: 18 games

Extract the answer to the question from the following context. Question: If Florida, for instance, did not have representation in the federal government, what would not be being followed? Context: Some federal constitutions also provide that certain constitutional amendments cannot occur without the unanimous consent of all states or of a particular state. The US constitution provides that no state may be deprived of equal representation in the senate without its consent. In Australia, if a proposed amendment will specifically impact one or more states, then it must be endorsed in the referendum held in each of those states. Any amendment to the Canadian constitution that would modify the role of the monarchy would require unanimous consent of the provinces. The German Basic Law provides that no amendment is admissible at all that would abolish the federal system.
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Answer:
US constitution