Problem: Light is the signal by which plants synchronize their internal clocks to their environment and is sensed by a wide variety of photoreceptors. Red and blue light are absorbed through several phytochromes and cryptochromes. One phytochrome, phyA, is the main phytochrome in seedlings grown in the dark but rapidly degrades in light to produce Cry1. Phytochromes B–E are more stable with phyB, the main phytochrome in seedlings grown in the light. The cryptochrome (cry) gene is also a light-sensitive component of the circadian clock and is thought to be involved both as a photoreceptor and as part of the clock's endogenous pacemaker mechanism. Cryptochromes 1–2 (involved in blue–UVA) help to maintain the period length in the clock through a whole range of light conditions.
What signals plants to synchronize their internal clocks?
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Answer: Light


Problem: The State of Israel is divided into six main administrative districts, known as mehozot (מחוזות; singular: mahoz) – Center, Haifa, Jerusalem, North, Southern, and Tel Aviv Districts, as well as the Judea and Samaria Area in the West Bank. All of the Judea and Samaria Area and parts of the Jerusalem and North districts are not recognized internationally as part of Israel. Districts are further divided into fifteen sub-districts known as nafot (נפות; singular: nafa), which are themselves partitioned into fifty natural regions.
How many sub-districts are there?
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Answer: fifteen


Problem: The show itself is popular in the Southern United States, with households in the Southeastern United States 10% more likely to watch American Idol during the eighth season in 2009, and those in the East Central region, such as Kentucky, were 16 percent more likely to tune into the series. Data from Nielsen SoundScan, a music-sales tracking service, showed that of the 47 million CDs sold by Idol contestants through January 2010, 85 percent were by contestants with ties to the American South.
How many CDS were sold by Idol contestants up to 2010?
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Answer:
47 million