Article: 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.

Question: What is theorized to have evolved with circadian rhythms?
Ans: photosensitive proteins


Article: Some alloys occur naturally, such as electrum, which is an alloy that is native to Earth, consisting of silver and gold. Meteorites are sometimes made of naturally occurring alloys of iron and nickel, but are not native to the Earth. One of the first alloys made by humans was bronze, which is made by mixing the metals tin and copper. Bronze was an extremely useful alloy to the ancients, because it is much stronger and harder than either of its components. Steel was another common alloy. However, in ancient times, it could only be created as an accidental byproduct from the heating of iron ore in fires (smelting) during the manufacture of iron. Other ancient alloys include pewter, brass and pig iron. In the modern age, steel can be created in many forms. Carbon steel can be made by varying only the carbon content, producing soft alloys like mild steel or hard alloys like spring steel. Alloy steels can be made by adding other elements, such as molybdenum, vanadium or nickel, resulting in alloys such as high-speed steel or tool steel. Small amounts of manganese are usually alloyed with most modern-steels because of its ability to remove unwanted impurities, like phosphorus, sulfur and oxygen, which can have detrimental effects on the alloy. However, most alloys were not created until the 1900s, such as various aluminium, titanium, nickel, and magnesium alloys. Some modern superalloys, such as incoloy, inconel, and hastelloy, may consist of a multitude of different components.

Question: What metal is made by combining tin and copper?
Ans: bronze


Article: Bacteria are further divided into lithotrophs that use inorganic electron donors and organotrophs that use organic compounds as electron donors. Chemotrophic organisms use the respective electron donors for energy conservation (by aerobic/anaerobic respiration or fermentation) and biosynthetic reactions (e.g., carbon dioxide fixation), whereas phototrophic organisms use them only for biosynthetic purposes. Respiratory organisms use chemical compounds as a source of energy by taking electrons from the reduced substrate and transferring them to a terminal electron acceptor in a redox reaction. This reaction releases energy that can be used to synthesise ATP and drive metabolism. In aerobic organisms, oxygen is used as the electron acceptor. In anaerobic organisms other inorganic compounds, such as nitrate, sulfate or carbon dioxide are used as electron acceptors. This leads to the ecologically important processes of denitrification, sulfate reduction, and acetogenesis, respectively.

Question: What do lithotrophs use ?
Ans: inorganic electron donors


Article: Although Ottoman madaris had a number of different branches of study, such as calligraphic sciences, oral sciences, and intellectual sciences, they primarily served the function of an Islamic centre for spiritual learning. "The goal of all knowledge and in particular, of the spiritual sciences is knowledge of God." Religion, for the most part, determines the significance and importance of each science. As İnalcık mentions: "Those which aid religion are good and sciences like astrology are bad." However, even though mathematics, or studies in logic were part of the madrasa's curriculum, they were all centred around religion. Even mathematics had a religious impulse behind its teachings. "The Ulema of the Ottoman medreses held the view that hostility to logic and mathematics was futile since these accustomed the mind to correct thinking and thus helped to reveal divine truths" – key word being "divine". İnalcık also mentions that even philosophy was only allowed to be studied so that it helped to confirm the doctrines of Islam." Hence, madaris – schools were basically religious centres for religious teachings and learning in the Ottoman world. Although scholars such as Goffman have argued that the Ottomans were highly tolerant and lived in a pluralistic society, it seems that schools that were the main centres for learning were in fact heftily religious and were not religiously pluralistic, but centred around Islam. Similarly, in Europe "Jewish children learned the Hebrew letters and texts of basic prayers at home, and then attended a school organised by the synagogue to study the Torah." Wiesner-Hanks also says that Protestants also wanted to teach "proper religious values." This shows that in the early modern period, Ottomans and Europeans were similar in their ideas about how schools should be managed and what they should be primarily focused on. Thus, Ottoman madaris were very similar to present day schools in the sense that they offered a wide range of studies; however, these studies, in their ultimate objective, aimed to further solidify and consolidate Islamic practices and theories.

Question: What was the essential mission of Islamic schools in the Ottoman Empire?
Ans:
spiritual learning