1
$\begingroup$

If you have two parents that have the eye-color genes Bb and Bb and they have a baby, what is the probability that the baby has blue eyes?

all of the possible allele combinations that the baby could inherit from her parents are: BB, Bb, bB, bb.

In this problem, is it right to see the allele combinations Bb and bB as a single combination and, thus, say that the number of the total outcomes is 3?

$\endgroup$
4
$\begingroup$

If the first allele denotes the allele inherited from the father and the second allele denotes the allele inherited from the mother, then there are four equally likely outcomes: BB, Bb, bB, and bb.

If you wish to simply represent the potential genotypes of a child, there are three possible outcomes, where we do not distinguish between the allele inherited from the father and the allele inherited from the mother. They are BB, which occurs with probability $0.25$; Bb, which occurs with probability $0.50$; and bb, which occurs with probability $0.25$.

| cite | improve this answer | |
$\endgroup$
1
$\begingroup$

There are only 3 outcomes, but they do not have equal probability. You can split the Bb outcome into two cases (which are distinct in origin but identical in result), and now you do have 4 equally probable cases.

| cite | improve this answer | |
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.