QUES: It is not clearly documented when the title of the Grand Duke was first introduced, but the importance of the Kiev principality was recognized after the death of Sviatoslav I in 972 and the ensuing struggle between Vladimir the Great and Yaropolk I. The region of Kiev dominated the state of Kievan Rus' for the next two centuries. The Grand Prince ("velikiy kniaz'") of Kiev controlled the lands around the city, and his formally subordinate relatives ruled the other cities and paid him tribute. The zenith of the state's power came during the reigns of Vladimir the Great (980–1015) and Prince Yaroslav I the Wise (1019–1054). Both rulers continued the steady expansion of Kievan Rus' that had begun under Oleg.

When was the title of Grand Duke introduced?
What is the answer?
ANS: unanswerable
QUES: Native Sumerian rule re-emerged for about a century in the Neo-Sumerian Empire or Third Dynasty of Ur (Sumerian Renaissance) approximately 2100-2000 BC, but the Akkadian language also remained in use. The Sumerian city of Eridu, on the coast of the Persian Gulf, is considered to have been the world's first city, where three separate cultures may have fused — that of peasant Ubaidian farmers, living in mud-brick huts and practicing irrigation; that of mobile nomadic Semitic pastoralists living in black tents and following herds of sheep and goats; and that of fisher folk, living in reed huts in the marshlands, who may have been the ancestors of the Sumerians.

When was the Third Dynasty of Ur?
What is the answer?
ANS: approximately 2100-2000 BC
QUES: De novo or "orphan" genes, whose sequence shows no similarity to existing genes, are extremely rare. Estimates of the number of de novo genes in the human genome range from 18 to 60. Such genes are typically shorter and simpler in structure than most eukaryotic genes, with few if any introns. Two primary sources of orphan protein-coding genes are gene duplication followed by extremely rapid sequence change, such that the original relationship is undetectable by sequence comparisons, and formation through mutation of "cryptic" transcription start sites that introduce a new open reading frame in a region of the genome that did not previously code for a protein.

What is one primary source of orphan protein-coding genes?
What is the answer?
ANS:
gene duplication followed by extremely rapid sequence change