Hardy-Weinberg Law?

Question

Can anyone please explain these formulas and the law for me. I'm in AP Bio and my teacher sucks, and I have no idea what to do. Thanks.

Answer 1

When I use X^2 I mean X squared or XX

If you had algebra you studied (X+Y)^2 = x^2+2XY+Y^2

Hardy Weinberg is (p+q)=1 and (p+q)^2=(p + q) (p + q)=1
same as the top line p^2+2pq+q^2

p stands for the dominant allele
q stands for the recessive allele

In a population of 4300 33 people have the recessive condition rr. However you know there are some recessive alleles masked in the heterozygous state Rr.
Therefore 4267 people are RR or Rr + 33 people are rr
4267 means 8534 alleles
33 means 66 alleles
total population of 8600 alleles

frequency of gene r --> f(r) = (66+1/2 Rr)/8600 = q
f (R)= (RR+1/2 Rr)/8600 = p
(p+q)=1
(66+1/2 Rr)/8600 + (RR+1/2 Rr)/8600 = 1

frequency of Rr = 2pq The frequency of heterozygotes is twice the product of the two gene frequencies.
f(rr) = qq The frequency of homozygotes is the gene frequency squared
f(RR) = pp = [(RR+1/2 Rr)/8600] x [(RR+1/2 Rr)/8600]

Answer 2

Hi - I've posted a introduction to the topic here: http://medicguide.blogspot.com/2007/11/feature-hardy-weinberg-equation-and.html

Hope it helps - if you've got any further questions, just email me.

Answer 3

For very general ideas, you can visit Wikipedia, at:

http://en.wikipedia.org/wiki/Hardy-Weinberg_principle

But, since you've also indicated you're in AP, you might also try the following, which has more detail:

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/H/Hardy_Weinberg.html

Hope this helps - good luck.