Question

which of the following information is available in a punnett square showing the inheritance pattern for an autosomal recessive disorder?
tt × tt
tt
tt
tt
tt
percentage of all children likely to be affected by the disorder
number of children born to the two parents
percentage of females likely to be affected by the disorder
percentage of males likely to be affected by the disorder

Explanation:

Step1: Analyze the Punnett square

In the given Punnett square \(Tt\times tt\), the possible genotypes of the offspring are \(Tt\) and \(tt\). For an autosomal - recessive disorder, the recessive phenotype (affected by the disorder) is shown by the genotype \(tt\).

Step2: Calculate the proportion

There are 4 boxes in the Punnett square. The number of \(tt\) (affected) genotypes is 2. The proportion of affected offspring is \(\frac{2}{4}=\frac{1}{2} = 50\%\). The Punnett square gives the probability (percentage) of all children (regardless of sex, since it's autosomal) being affected. It does not give the actual number of children (\(Tt\times tt\) could have any number of children in reality, the Punnett square is a probability - based prediction). Also, since it's autosomal (not sex - linked), there is no difference in probability between males and females.

Answer:

percentage of all children likely to be affected by the disorder