: 11 The later definition by Cavalli-Sforza & Bodmer (1971) is currently used: Genetic polymorphism is the occurrence in the same population of two or more alleles at one locus, each with appreciable frequency, where the minimum frequency is typically taken as 1%.
The financial world splits up its calendar into four quarters, each three months long. If January to March is the first quarter, April to June is the second quarter, and so on, though a company's first quarter does not have to begin in January.
On a college academic calendar, quarters are typically 10 weeks long, plus one additional week for finals. A full academic year, not including summer, is 3 quarters. So if one does not go to summer school, 7 quarters would be 2 full academic years, plus one additional quarter. If you do go to summer school, 7 quarters would be 2 full academic years, plus the summer quarter between those two years. Most full time students take 3 to 4 classes at a time on the quarter system.