In fruit flies, straight wing shape is dominant to curly wing shape. A particular population of fruit flies is in Hardy-Weinberg equilibrium with respect to the alleles for wing shape. The Hardy-Weinberg equation, given below, is useful in understanding population genetics: P2 + 2pq + q2 = 1
a. Explain what the terms (p2, 2pq, and q2) represent in the population of fruit flies?
b. Describe one condition that is necessary for the population to be in equilibrium?

a) p² = homozygous dominant genotype frequency

   2pq = heterozygous genotype frequency

   q² = homozygous recessive genotype frequency

b) the population must be randomly mating.

Explanation:

(a) The formula for genotype frequency of a population with p and q alleles is as under:

        p² + 2pq + q²  = 1

where p allele is dominant over q allele.

Phenotypically p² + 2pq will produce same appearance i.e. dominant phenotype while q² will produce recessive phenotype. So it means that if 80% population is represented by p² + 2pq then 20% will be represented by q².

(b) One of the conditions for a population to be in Hardy-Weinberg equilibrium is that the population must be randomly mating.

americans began to notice growing differences between the northern and southern sections of the country. there were more people living in cities in the north, which made it more urban. more people lived on farms in the south, which made it more rural. while many people were farmers in the northern states, there were now other ways to make a living, such as working in mechanical cotton gins factories manufacturing cloth, tools and other goods. people in the north supported high tariffs on goods imported from europe because the extra cost encouraged people to “buy american” instead. in the southern states, planters did not like tariffs because they sold most of their production to europe and bought their tools from there as well. southerners believed the protective tariff was something that only northern factory owners keep their profits high. so the southern politicians came up with an idea. they would opt out. they would simply ignore the protective tariff. it was ‘null and void’ in south carolina. the state would not collect the taxes on goods imported into south carolina, no matter what the president said they had to do. this decision led to the nullification crisis.