Tongue Rolling
Given that the ability to roll a tongue is a dominant trait, if a heterozygous tongue-roller marries a non-tongue roller , what is the probability that their child is a non-tongue roller ?
Punnett squares are used to estimate the probability of inheriting a certain gene by crossing the alleles from both parents. A capitalized letter is used to show a dominant trait while a non-capitalized letter shows a recessive trait. Here's an example:
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1 solution
As Steven is heterozygous for the particular trait, his genes must be of the form Xx . And as Natalie must be having homozygous recessive condition as she can't roll her tongue hence it should be xx . Now let's draw a punnet square:
x x X Xx Xx x xx xx
From the table, we can easily deduce that the probability of their child being a non-roller is 5 0 %