possible question
Question: A simple example of using tree diagrams is in dominant and recessive gene inheritance. Consider the allele pair of genes, R and B, which only affect the women in a family.
Let the probabilities of this gene being passed down be:
| Daughter has R gene | Daughter has B gene | |
| Mother has R gene | 2/3 | 1/3 |
| Mother has B gene | 1/3 | 2/3 |
What is the probability that woman A has two daughters with the B gene, and one with the R gene? What is the probability that a woman with four daughters, has three with the B gene, and one with the R gene?
Don't forget to include the likelihood of a woman having a female child.