00:01
We have a population in hardy -vinberg equilibrium.
00:03
There are 1 ,375 dominant allele's present, and the population is 1 ,250 individuals.
00:12
How many people are heterozygotes? so when i see a question about hardy -binberg, i write out these two equations.
00:21
2pq plus q squared equals 1.
00:23
So this top one is for the allele frequency, and this bottom one is for the genotype frequency.
00:29
So i'll put those to the side, and let's see what we've got here.
00:33
So this population has 1 ,250 individuals.
00:39
Each individual has two copies of the gene.
00:44
So this means that in 1 ,250 individuals, we have 2 ,500 copies of the gene.
00:52
And each copy is going to be either the dominant allele p or the recessive allele q.
00:58
We know that 1 ,375 dominant alleles are present.
01:04
So of this 2 ,500, there are 1 ,375 copies of p, which means the rest are going to be q, but this is enough information for us to get p, which is the frequency of this.
01:22
So let's get the frequency of the algorithm.
01:26
1375 divided by 2 ,500 is equal to p, which is going to be 0 .55.
01:38
So all of the other copies are q, so q is going to be 0 .45, because p plus q is equal to 1.
01:46
So now we have the allele frequency.
01:49
If you get all of these copies of gene, 55 % of them are a p and 45 % of them are a q.
01:57
Again, p is for dominant allelial, q is for recessive.
02:01
Now, how many people are heterozygotes? so now we look at the genotype frequency...