This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

[Q]: Gene nomenclature has been established by the HUGO Gene Nomenclature Committee (HGNC) for each known human gene in the form of an approved gene name and symbol (short-form abbreviation), which can be accessed through a database maintained by HGNC. Symbols are chosen to be unique, and each gene has only one symbol (although approved symbols sometimes change). Symbols are preferably kept consistent with other members of a gene family and with homologs in other species, particularly the mouse due to its role as a common model organism.
[A]: What committee has established gene nomenclature for every known human gene?

[Q]: The 197374 season saw the arrival of Johan Cruyff, who was bought for a world record 920,000 from Ajax. Already an established player with Ajax, Cruyff quickly won over the Barcelona fans when he told the European press that he chose Barcelona over Real Madrid because he could not play for a club associated with Francisco Franco. He further endeared himself when he named his son Jordi, after the local Catalan Saint George. Next to champions like Juan Manuel Asensi, Carles Rexach and Hugo Sotil, he helped the club win the 197374 season for the first time since 1960, defeating Real Madrid 50 at the Bernabeu along the way. He was crowned European Footballer of the Year in 1973 during his first season with Barcelona (his second Ballon d'Or win; he won his first while playing for Ajax in 1971). Cruyff received this prestigious award a third time (the first player to do so) in 1974, while he was still with Barcelona.
[A]: When did Johan Cruyff join Barcelona?

[Q]: 50 Hz systems support three scanning rates: 50i, 25p and 50p. 60 Hz systems support a much wider set of frame rates: 59.94i, 60i, 23.976p, 24p, 29.97p, 30p, 59.94p and 60p. In the days of standard definition television, the fractional rates were often rounded up to whole numbers, e.g. 23.976p was often called 24p, or 59.94i was often called 60i. 60 Hz high definition television supports both fractional and slightly different integer rates, therefore strict usage of notation is required to avoid ambiguity. Nevertheless, 29.97i/59.94i is almost universally called 60i, likewise 23.976p is called 24p.
[A]:
What three scanning rates do 50 Hz systems support?