Problem: What drove circadian rhythms to evolve has been an enigmatic question. Previous hypotheses emphasized that photosensitive proteins and circadian rhythms may have originated together in the earliest cells, with the purpose of protecting replicating DNA from high levels of damaging ultraviolet radiation during the daytime. As a result, replication was relegated to the dark. However, evidence for this is lacking, since the simplest organisms with a circadian rhythm, the cyanobacteria, do the opposite of this - they divide more in the daytime. Recent studies instead highlight the importance of co-evolution of redox proteins with circadian oscillators in all three kingdoms of life following the Great Oxidation Event approximately 2.3 billion years ago. The current view is that circadian changes in environmental oxygen levels and the production of reactive oxygen species (ROS) in the presence of daylight are likely to have driven a need to evolve circadian rhythms to preempt, and therefore counteract, damaging redox reactions on a daily basis.
What developed to protect replicating DNA from ultraviolet radiation and night?
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Answer: unanswerable

Problem: Since June 2009 VidZone has offered a free music video streaming service in Europe, Australia and New Zealand. In October 2009, Sony Computer Entertainment and Netflix announced that the Netflix streaming service would also be available on PlayStation 3 in the United States. A paid Netflix subscription was required for the service. The service became available in November 2009. Initially users had to use a free Blu-ray disc to access the service; however, in October 2010 the requirement to use a disc to gain access was removed.
What do you have to disagree to with Netflix before you can use their service on PlayStation 3?
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Answer: unanswerable

Problem: The language possesses five vowels (or six, under the St. Petersburg Phonological School), which are written with different letters depending on whether or not the preceding consonant is palatalized. The consonants typically come in plain vs. palatalized pairs, which are traditionally called hard and soft. (The hard consonants are often velarized, especially before front vowels, as in Irish). The standard language, based on the Moscow dialect, possesses heavy stress and moderate variation in pitch. Stressed vowels are somewhat lengthened, while unstressed vowels tend to be reduced to near-close vowels or an unclear schwa. (See also: vowel reduction in Russian.)
Who says Russian has 6 vowels?
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Answer:
St. Petersburg Phonological School