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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 BE 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 12 (involved in blueUVA) help to maintain the period length in the clock through a whole range of light conditions.

What signals plants to synchronize their internal clocks?
Answer: Light
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Many Sanskrit dramas also indicate that the language coexisted with Prakrits, spoken by multilingual speakers with a more extensive education. Sanskrit speakers were almost always multilingual. In the medieval era, Sanskrit continued to be spoken and written, particularly by learned Brahmins for scholarly communication. This was a thin layer of Indian society, but covered a wide geography. Centres like Varanasi, Paithan, Pune and Kanchipuram had a strong presence of teaching and debating institutions, and high classical Sanskrit was maintained until British times.

How large of a group in society use Sanskrit?
Answer: thin layer
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San Diego is served by the San Diego Trolley light rail system, by the SDMTS bus system, and by Coaster and Amtrak Pacific Surfliner commuter rail; northern San Diego county is also served by the Sprinter light rail line. The Trolley primarily serves downtown and surrounding urban communities, Mission Valley, east county, and coastal south bay. A planned Mid-Coast extension of the Trolley will operate from Old Town to University City and the University of California, San Diego along the I-5 Freeway, with planned operation by 2018. The Amtrak and Coaster trains currently run along the coastline and connect San Diego with Los Angeles, Orange County, Riverside, San Bernardino, and Ventura via Metrolink and the Pacific Surfliner. There are two Amtrak stations in San Diego, in Old Town and the Santa Fe Depot downtown. San Diego transit information about public transportation and commuting is available on the Web and by dialing "511" from any phone in the area.

How many Amtrak stations are in San Diego?
Answer:
two