# HW ANS - 2 = .002 or .2% 3. After graduation, you and 19...

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1. If 9% of an African population is born with a severe form of sickle-cell anemia (ss), what percentage of the population will be more resistant to malaria because they are heterozygous (Ss) for the sickle-cell gene? 9% =.09 = ss = q 2 s = q = √(.09) = .3 p = 1 - .3 = .7 2pq = 2 (.7 x .3) = .42 = 42% of the population are heterozygotes (carriers) 2. This is a classic data set on wing coloration in the scarlet tiger moth (Panaxia dominula). Coloration in this species had been previously shown to behave as a single-locus, two-allele system with incomplete dominance. Data for 1612 individuals are given below: White-spotted (AA) =1469; Intermediate (Aa) = 138; Little spotting (aa) =5 Calculate the following frequencies: A, a, AA, Aa, aa ( f) A = (2 * (1469) + (138))/(2 * (1469 + 138 + 5)) = .954 or 95.4% ( f )a = 1 - .954 = .046 or 4.6% ( f )AA = (.954) 2 = .910 or 91% ( f )Aa = 2 (.954)(.046) = .087 or 8.7% ( f )aa = (.046)

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Unformatted text preview: 2 = .002 or .2% 3. After graduation, you and 19 friends build a raft, sail to a deserted island, and start a new population, totally isolated from the world. Two of your friends carry (that is, are heterozygous for) the recessive cf allele, which in homozygotes causes cystic fibrosis. a) Assuming that the frequency of this allele does not change as the population grows, what will be the instance of cystic fibrosis on your island? There are 40 total alleles of the 20 people of which 2 alleles are cystic fibrosis causing. 2/40 = .05 the frequency of the cystic fibrosis allele thus cc or q 2 = (.05) 2 =.0025 or . 25% of the population will be born with cystic fibrosis. b) Cystic fibrosis births on the island are how many times greater than the original mainland. The frequency of births on the mainland is .059%. 0.25/.059 = about 4 times greater occurrence...
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## This note was uploaded on 03/20/2012 for the course BIOLOGY 1305 taught by Professor Adair during the Spring '09 term at Baylor.

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HW ANS - 2 = .002 or .2% 3. After graduation, you and 19...

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