Within a population of butterflies the allele for the color

Within a population of butterflies, the allele for the color black (B) is incompletely dominant over the allele for the color white (b). A survey of the population finds 42 black butterflies, 47 white butterflies, and 11 gray butterflies.

• Is this population in HW equilibrium? Show your work

• Describe what might explain the phenotype and genotype proportions we see in this population.

Solution

ans

To show that the population is in hardy weinberg equilibrium

Well, before you start, note that the allelic frequencies are p and q, and be sure to note that we don\'t have nice round numbers and the total number of individuals counted

42+47+11= 100

since Black colour is incompletely dominant over white then

since white is recessive then q^{2 =} 47/100= .47

p² =42/100= .42

also according to hardy weinberg law p+q=1

but this population is not in hardyweinberg equation according to above formula

2.

Mendel’s results were groundbreaking partly because they contradicted the (then-popular) idea that parents\' traits were permanently blended in their offspring. In some cases, however, the phenotype of a heterozygous organism can actually be a blend between the phenotypes of its homozygous parents.

For example, in the snapdragon, Antirrhinum majus, a cross between a homozygous white-flowered plant (C^WC^WCWCWC, start superscript, W, end superscript, C, start superscript, W, end superscript) and a homozygous red-flowered plant (C^RC^RCRCRC, start superscript, R, end superscript, C, start superscript, R, end superscript) will produce offspring with pink flowers (C^RC^WCRCWC, start superscript, R, end superscript, C, start superscript, W, end superscript). This type of relationship between alleles, with a heterozygote phenotype intermediate between the two homozygote phenotypes, is called incomplete dominance.