Question: Essential genes are the set of genes thought to be critical for an organism's survival. This definition assumes the abundant availability of all relevant nutrients and the absence of environmental stress. Only a small portion of an organism's genes are essential. In bacteria, an estimated 250400 genes are essential for Escherichia coli and Bacillus subtilis, which is less than 10% of their genes. Half of these genes are orthologs in both organisms and are largely involved in protein synthesis. In the budding yeast Saccharomyces cerevisiae the number of essential genes is slightly higher, at 1000 genes (~20% of their genes). Although the number is more difficult to measure in higher eukaryotes, mice and humans are estimated to have around 2000 essential genes (~10% of their genes).
Is there an answer to this question: What are the set of genes which are thought to be crucial for the survival of an organism?

Answer: Essential genes

Question: The region was dominated by Bantu-speaking tribes, who built trade links leading into the Congo River basin. Congo-Brazzaville was formerly part of the French colony of Equatorial Africa. Upon independence in 1960, the former colony of French Congo became the Republic of the Congo. The People's Republic of the Congo was a MarxistLeninist one-party state from 1970 to 1991. Multi-party elections have been held since 1992, although a democratically elected government was ousted in the 1997 Republic of the Congo Civil War and President Denis Sassou Nguesso has ruled for 26 of the past 36 years.
Is there an answer to this question: What year was President Denis Sassou Nguesso ousted?

Answer: unanswerable

Question: In the Treaty of Paris after the Revolution, the British had ceded the lands between the Appalachian Mountains and the Mississippi River to the United States, without consulting the Shawnee, Cherokee, Choctaw and other smaller tribes who lived there. Because many of the tribes had fought as allies of the British, the United States compelled tribal leaders to sign away lands in postwar treaties, and began dividing these lands for settlement. This provoked a war in the Northwest Territory in which the U.S. forces performed poorly; the Battle of the Wabash in 1791 was the most severe defeat ever suffered by the United States at the hands of American Indians. President Washington dispatched a newly trained army to the region, which decisively defeated the Indian confederacy at the Battle of Fallen Timbers in 1794.
Is there an answer to this question: What was the decisive battle in the Northwest territories against the native population there?

Answer: the Battle of Fallen Timbers

Question: The chemical composition of wood varies from species to species, but is approximately 50% carbon, 42% oxygen, 6% hydrogen, 1% nitrogen, and 1% other elements (mainly calcium, potassium, sodium, magnesium, iron, and manganese) by weight. Wood also contains sulfur, chlorine, silicon, phosphorus, and other elements in small quantity.
Is there an answer to this question: What approximate percentage of carbon does wood have?

Answer:
50%