Question: 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.
Is there an answer to this question: What type of proteins developed as a result of circadian rhythms?

Answer: unanswerable


Question: The more long term the exposure to stress is, the more impact it may have. However, short term exposure to stress also causes impairment in memory by interfering with the function of the hippocampus. Research shows that subjects placed in a stressful situation for a short amount of time still have blood glucocorticoid levels that have increased drastically when measured after the exposure is completed. When subjects are asked to complete a learning task after short term exposure they have often difficulties. Prenatal stress also hinders the ability to learn and memorize by disrupting the development of the hippocampus and can lead to unestablished long term potentiation in the offspring of severely stressed parents. Although the stress is applied prenatally, the offspring show increased levels of glucocorticoids when they are subjected to stress later on in life.
Is there an answer to this question: Does it matter how long someone is exposed to stress to have an impact on their memory?

Answer: the more impact it may have. However, short term exposure to stress also causes impairment in memory by interfering with the function of the hippocampus


Question: Historically, the population of Tibet consisted of primarily ethnic Tibetans and some other ethnic groups. According to tradition the original ancestors of the Tibetan people, as represented by the six red bands in the Tibetan flag, are: the Se, Mu, Dong, Tong, Dru and Ra. Other traditional ethnic groups with significant population or with the majority of the ethnic group residing in Tibet (excluding a disputed area with India) include Bai people, Blang, Bonan, Dongxiang, Han, Hui people, Lhoba, Lisu people, Miao, Mongols, Monguor (Tu people), Menba (Monpa), Mosuo, Nakhi, Qiang, Nu people, Pumi, Salar, and Yi people.
Is there an answer to this question: Which country has a disputed area with Tibet?

Answer: India


Question: They invented and developed arithmetic by using several different number systems including a mixed radix system with an alternating base 10 and base 6. This sexagesimal system became the standard number system in Sumer and Babylonia. They may have invented military formations and introduced the basic divisions between infantry, cavalry, and archers. They developed the first known codified legal and administrative systems, complete with courts, jails, and government records. The first true city-states arose in Sumer, roughly contemporaneously with similar entities in what are now Syria and Lebanon. Several centuries after the invention of cuneiform, the use of writing expanded beyond debt/payment certificates and inventory lists to be applied for the first time, about 2600 BC, to messages and mail delivery, history, legend, mathematics, astronomical records, and other pursuits. Conjointly with the spread of writing, the first formal schools were established, usually under the auspices of a city-state's primary temple.
Is there an answer to this question: What type of formations is it possible Sumerians invented?

Answer:
military