QUES: 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 250–400 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).

What does the definition of essential genes assume an absence of?
What is the answer?
ANS: environmental stress
QUES: The advent of the Industrial Revolution in Britain provided a great boost to cotton manufacture, as textiles emerged as Britain's leading export. In 1738, Lewis Paul and John Wyatt, of Birmingham, England, patented the roller spinning machine, as well as the flyer-and-bobbin system for drawing cotton to a more even thickness using two sets of rollers that traveled at different speeds. Later, the invention of the James Hargreaves' spinning jenny in 1764, Richard Arkwright's spinning frame in 1769 and Samuel Crompton's spinning mule in 1775 enabled British spinners to produce cotton yarn at much higher rates. From the late 18th century on, the British city of Manchester acquired the nickname "Cottonopolis" due to the cotton industry's omnipresence within the city, and Manchester's role as the heart of the global cotton trade.

When was a new spinning machine patented that boosted cotton production?
What is the answer?
ANS: 1738
QUES: The urban AC stations resemble soft AC rather than hot AC; they play predominantly R&B and soul music with little hip-hop. This is reflected in many of the urban AC radio stations' taglines, such as "Today's R&B and classic soul", "The best variety of R&B hits and oldies" and "(City/Region)'s R&B leader". Urban AC's core artists include Luther Vandross, Trey Songz, Patti LaBelle, Toni Braxton, Whitney Houston, Aretha Franklin, Frank Ocean, Craig David and Mariah Carey.

What other adult contemporary radio format is urban AC similar to?
What is the answer?
ANS:
soft AC