Suppose "A" is a dominant gene for the ability to taste phenylthiocarbamide and "a" is a recessive gene for inability to taste it. Which of the following couples could possibly have both a child who tastes it and a child who does not?

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Quizplus · Accepted Answer

In the Aa x Aa (C) cross, there is a possibility of producing offspring with different genotypes: AA, Aa, and aa. Both AA and Aa genotypes have the dominant A allele which allows the ability to taste PTC. Therefore, if an AA or Aa individual is produced in this cross, they will be able to taste PTC. On the other hand, the aa genotype has two recessive a alleles, which means the individual will not be able to taste PTC. Therefore, if an aa individual is produced in this cross, they will not be able to taste PTC. Thus, it is possible for this couple to have one child who can taste PTC (AA or Aa) and another who cannot (aa).

Suppose "A" Is a Dominant Gene for the Ability to Taste