Why is this technique Punnett squares used to calculate the probability of genotypes and phenotypes of one child. In other words, why is it inappropriate to say "Two out of four of their children will have brown hair? I don’t understand this help m

A Punnett square allows the prediction of the percentages of phenotypes in the offspring of a cross from known genotypes. A Punnett square can be used to determine a missing genotype based on the other genotypes involved in a cross. It is inappropriate to say  "Two out of four of their children will have brown hair because the genes could are not always going to give you what you think you are going to get. Using punnett squares just predicts the outcome, but doesn't necessarily know 100%

Explanation:

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