When looking at snapdragons, the dominant flowers are red (R) and the recessive flowers are white (r). This plant displays incomplete dominance since heterozygotes have flowers that are pink. If we look at population of 100 snapdragons with 50 having have pink flowers and 25 having white flowers, what is the frequency of homozygous dominant individuals in the population?
a. 0.5
b. 0.30
c. 1
d. 0.75
e. 0.25
I'm confused. When i worked it out, I got the answer E) 0.25 but when i compared it to my friend's, she got A) 0.5.
Can someone please clarify what the correct answer is and how?
Please and thank you in advance!
a. 0.5
b. 0.30
c. 1
d. 0.75
e. 0.25
I'm confused. When i worked it out, I got the answer E) 0.25 but when i compared it to my friend's, she got A) 0.5.
Can someone please clarify what the correct answer is and how?
Please and thank you in advance!
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You are correct. You're looking for the value p^2 (that's, by definition, the frequency of homozygous dom. individuals). You are given that 2pq = 0.5, and q^2 = 0.25 from the question. So, q = 0.5 from doing the math, and p + q = 1. From this you know that p = 0.5. Your friend made the mistake of thinking that she was done here, but you have to square p to get the frequency of homozygous dominant individuals, so the answer is 0.25.