Concept explainers
The frequency of tasters and nontasters of PTC (see Problem
a. Calculate the frequency of the dominant (T) allele for PTC tasting and the recessive (t) allele for nontasting in each population.
b. Assuming that Hardy
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- In 1927, the ophthalmologist George Waaler tested9049 schoolboys in Oslo, Norway, for red-green colorblindness and found 8324 of them to be normal and725 to be color blind. He also tested 9072 schoolgirlsand found 9032 that had normal color vision while40 were color blind.a. Assuming that the same sex-linked recessive allelec causes all forms of red-green color blindness,calculate the allele frequencies of c and C (the allelefor normal vision) from the data for the schoolboys.(Hint: Refer to your answer to Problem 12a.)b. Does Waaler’s sample demonstrate Hardy-Weinbergequilibrium for alleles of this gene? Explain youranswer by describing observations that are eitherconsistent or inconsistent with this hypothesis.On closer analysis of these schoolchildren, Waalerfound that there was actually more than one c allelecausing color blindness in his sample: one kind forthe prot type (cp) and one for the deuter type (cd).(Protanopia and deuteranopia are slightly differentforms of red-green…arrow_forwardConnection to Quantitative traits: SNPs are inherited in a Mendelian fashion and are often polygenic in nature. We can think of SNPs in terms of either contributing or non-contributing alleles. A study of SNPs correlated with heart disease has shown that heart problems are severe if 9 or more of the alleles at 6 loci are of the contributing variety. What is the probability the following parents will have a child that is susceptible heart disease? AaBbccDDEEFf x AaBbCCDdEeffarrow_forwardOrchids come in an amazing variety of colours. Scientists found that cloned Cattleya orchids have a phenotypic variance of 14, while wild Cattleya orchids have a phenotypic variance of 29. What is the broad-sense heritability of these orchids?arrow_forward
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