00:01
So polydactyl is inherited as an autosomal dominant trait, two individuals that are heterozygous for this trait, marry and plan a family of five children.
00:08
Assume a one -to -one sex ratio and the gene is completely penetrant, once the probability of the couple's five children will consist of at least three with polydaple.
00:17
So to start off, using what we're given from the problem, we have total children, which is n equals n equals five.
00:38
And then we have children with the dominant trait.
00:42
We'll have dominant bd of three.
00:46
And then for the recessive trait, we have two.
00:51
So our p in our equation will be three out of four.
00:57
And our q will be one out of four.
01:03
And this, so we can take this and find, and then find the probability of three dominant, and then two recessive.
01:17
And this will set up looking like n factorial divided by d factorial times r factorial.
01:32
And then this is also multiplied by p raised to the d times q raised to the r.
01:50
So now we have the equation...
