In a population of humans, the frequency of blue eyes is 0.09. If having blue eyes is the recessive phenotype, what is the frequency of the recessive allele?

0.3

Explanation:

According to the Hardy-Weinberg principle, in a population in equilibrium, where p is the dominant allele and q is the recessive allele,

Allele frequencies:

p + q = 1

Genotype frequencies:

where p² is the dominant h0m0zygous phenotype and q² is the recessive h0m0zygous phenotype, and 2pq is the heterozygote.

p² + 2pq + q² = 1,

where p² is the dominant h0m0zygous phenotype and q² is the recessive h0m0zygous phenotype, and 2pq is the heterozygote.

Since we know q² = the recessive h0m0zygous phenotype, and the frequency is 0.09

q = \sqrt{0.09} \\ = 1

=0.3

not sure if this is what you'r looking for eubacteria and archaebacteria

measuring light intensity

light meters can be used to measure light intensity. the meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

errors can be made when measuring light intensity by accidentally shading the light meter. the reliability of the results can be checked by taking many samples.