Problem: The relationship between genes can be measured by comparing the sequence alignment of their DNA.:7.6 The degree of sequence similarity between homologous genes is called conserved sequence. Most changes to a gene's sequence do not affect its function and so genes accumulate mutations over time by neutral molecular evolution. Additionally, any selection on a gene will cause its sequence to diverge at a different rate. Genes under stabilizing selection are constrained and so change more slowly whereas genes under directional selection change sequence more rapidly. The sequence differences between genes can be used for phylogenetic analyses to study how those genes have evolved and how the organisms they come from are related.
What type of analyses can the sequence differences between genes be used for?
The answer is the following: phylogenetic

Problem: The average population density was 11,457 people per square mile (4,405.4/km²). The Census reported that 1,468,623 people (96.2% of the population) lived in households, 38,007 (2.5%) lived in non-institutionalized group quarters, and 19,376 (1.3%) were institutionalized. In 2013, the city reported having 668,247 total housing units, down slightly from 670,171 housing units in 2010. As of 2013[update], 87 percent of housing units were occupied, while 13 percent were vacant, a slight change from 2010 where 89.5 percent of units were occupied, or 599,736 and 10.5 percent were vacant, or 70,435. Of the city's residents, 32 percent reported having no vehicles available while 23 percent had two or more vehicles available, as of 2013[update].
How many houses or apartments were there in 2010?
The answer is the following: 670,171

Problem: In the 2011–12 season, Arsenal celebrated their 125th year anniversary. The celebrations included a modified version of the current crest worn on their jerseys for the season. The crest was all white, surrounded by 15 oak leaves to the right and 15 laurel leaves to the left. The oak leaves represent the 15 founding members of the club who met at the Royal Oak pub. The 15 laurel leaves represent the design detail on the six pence pieces paid by the founding fathers to establish the club. The laurel leaves also represent strength. To complete the crest, 1886 and 2011 are shown on either sides of the motto "Forward" at the bottom of the crest.
What do the 15 oak leaves on the anniversary crest indicate?
The answer is the following: founding members

Problem: The International Commission on Illumination (CIE) is an international authority and standard defining organization on color and lighting. Publishing widely used standard metrics such as various CIE color spaces and the color rendering index.
What does the CIE stand for?
The answer is the following:
International Commission on Illumination