Frequency in Population?
Pink flowers are Homozygous dominant and White flowers are homozygous recessive. In 2009 white flowers comprised 8% of a population. What is the frequency of the homozygous dominant and heterozygous in this population?
- 1 decade agoFavorite Answer
You would want to use the Hardy-Weinberg Law for calculating this.
p^2=frequency of AA (homozygous dominant) in population
2pq=frequency of Aa (heterozygous) in population
q^2=frequency of aa (homozygous recessive) in population
Since q^2 is the aa in population (the white flowers) we know that q^2=8%, or q^2=0.08.
This would make q=0.2828.
You then have p^2+2p(0.2828)+(0.2828)^2=1
This leaves you with a quadratic, which when solved gives you p=0.7172
(I cheated on this step and used a quadratic equation solving app)
Now to solve for p^2 and 2pq
p^2=0.7172^2=0.514, or 51.4%
2pq=2*0.7172*0.2828=0.406 or 40.6%
So, you have
=51.4% AA (Homozygous dominant, pink flowers)
=40.6% Aa (Heterozygous, pink flowers)
To check, you can make sure that, with the 8% Homozygous recessive, this adds up to 100%
Or you could completely cheat and use this Hardy-Weinberg Calculator.
It's at least helpful for checking your answers if you need to show work.
- Anonymous1 decade ago
You're looking for the Hardy-Weinberg formula here:
p^2 + 2pq + q^2 = 1
You've been told that the homozygous recessives (p^2) are 8% (0.08). With this number, you can work out what p must be.
Then, do the maths.