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Q40 - Hardy-Weinberg and the Evolution of Lactose Tolerance

Theoretical A Real exam question - full text reproduced under IBO's CC BY-NC-SA 4.0 license

The proportion of lactose-tolerance in adults varies globally (Fig.). Lactose tolerance is a 1-locus dominant trait (dominant allele K and recessive allele k). Lactose tolerance (%) among adults around the world. A points to Greenland, B to Europe.

Figure 1. Figure 1.

Using the information and data, determine which of the statements are true or which are false.

A. Assuming that the European (B) population is in Hardy-Weinberg equilibrium, the frequency of K in the next generation will be 0.968
B. Differences in the frequencies of the K allele between populations prove that selection has been acting on this trait
C. In Greenland (A) where the percentage of lactose tolerance is 50%, the frequencies of the alleles k and K are equal
D. Lactose tolerance is assumed to be the ancestral trait among adult humans

Question reproduced from IBO 2015, Theoretical Exam A, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Community solutions (unofficial)