(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

The following pedigree shows that the trait is autosomal recessive. The probability of carriers in the population is 1/3. What is the probability that the child of III-3 and 4 is affected?

2. Relevant info

The answer provided is 1/36.

3. The attempt at a solution

The probability of II-3 being a carrier is 1/2 and that of II-4 is 1/3. The probability of two carriers having an affected child is 1/2. So the probability that II-3 and II-4 are carriers and their child is affected is 1/2 x1/3 x1/2=1/12.

(Edited to remove typo.)

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# What is the probability that the child is affected?

Have something to add?

**Physics Forums | Science Articles, Homework Help, Discussion**