00:01
Hello everyone, the question says that cystic fibrosis is an autosomal recessive disorder, that is if a person is homozygous for the recessive allele, he or she exhibits cystic fibrosis.
00:15
In the united states, approximately 1 out of 2 ,500 children are born with this disease.
00:22
Assuming hwe, what proportion of americans are carriers for cystic fibrosis? now let us take a look at the solution.
00:31
So the formula, it goes like p square plus 2pq plus q squared and p plus q.
00:44
It is equal to 1.
00:46
Now you'll see it is the frequency of the dominant allele of the population.
00:52
So this is frequency of dominant allele.
00:59
Alright, then q it is the frequency of the recessive allele.
01:04
P square is the percentage of homozygous dominant individuals.
01:10
So this is percentage of homozygous dominant.
01:14
After that q square it is the percentage of homozygous recessive.
01:19
After that, the 2pq it is the heterozygous individuals.
01:24
Okay? so we know that q it is the frequency of the recessive allele in the population and the population and from the above information, q square, it is equal to 1 upon 25 ,000, which is equal to 0 .004...