Question

2) If a gene locus for has two alleles and p is .33. What is q?

3) In a population of mice, coat color is controlled by a gene locus with two alleles, B and W. BB mice are brown, BW are tan and WW mice are white.

What is this type of inheritance called?

In this population there are 20 brown mice 15 tan mice and 30 white mice. Calculate p and q for this population where p = the allele frequency of B and q = the allele frequency of W?

4) An invasive moss begins to cover the ground of the island on which the beetles are found. In three years, the ground is completely covered in green moss. Birds are still the major predator of the beetle population. How do you predict this change would alter the allele frequency for color in the island beetle population?

5) If the green allele had been completely lost from the population and beetles only had the brown allele, how would the beetle population respond to the invasive moss in question 4? Why do you think genetic diversity is important for populations?

Answer 1

2)

According to Hardy-Weinberg equations;

p + q = 1
=> 0.33 + q = 1
=> q = 1 - 0.33 = 0.67

3)

The type of inheritance where the heterozygote has an 'intermediate' and mixed phenotype as compared to either homozygote is termed incomplete dominance.

2)

According to Hardy-Weinberg equations;

p + q = 1
=> 0.33 + q = 1
=> q = 1 - 0.33 = 0.67

3)

The type of inheritance where the heterozygote has an 'intermediate' and mixed phenotype as compared to either homozygote is termed incomplete dominance.

This population has 20 brown mice, 15 tan mice and 30 white mice. In other words, there are 20 mice of the genotype BB, 15 mice of the genotype Bb and 30 mice of the genotype bb.

Therefore,

p = Freq(B) = No. of B alleles in the population / Total Number of alleles
   = (No. of BB mice * 2 + No of Bb mice)/ Total No. of mice * 2
   = (20 * 2 + 15)/(20 + 15 + 30) * 2 = (40+15)/65 * 2 = 55/130 = 0.423

q = 1 - p = 1 - 0.423 = 0.577

4)

In the scenario where a green moss completely covers the ground the allele that codes for green bodcolor would rise in frequency as these beetles will be more successful at evading their predator and will therefore have more progeny.

5)

If the green allele were to be lost from the population, the beetle popuation would decline upon the invasion of the moss, since the beetles would be easier to spot for the birds, and there would be no Green beetles surviving, that could revive the population.

Genetic diversity is imporant as it allows a species to overcome selection against a particular trait. When negative selection against a particular trait occurs, this can result in a decline of the total population as well is there is not alternate allele that is not under negative selection.

This population has 20 brown mice, 15 tan mice and 30 white mice. In other words, there are 20 mice of the genotype BB, 15 mice of the genotype Bb and 30 mice of the genotype bb.

Therefore,

p = Freq(B) = No. of B alleles in the population / Total Number of alleles
   = (No. of BB mice * 2 + No of Bb mice)/ Total No. of mice * 2
   = (20 * 2 + 15)/(20 + 15 + 30) * 2 = (40+15)/65 * 2 = 55/130 = 0.423

q = 1 - p = 1 - 0.423 = 0.577

4)

In the scenario where a green moss completely covers the ground the allele that codes for green body color would rise in frequency as these beetles will be more successful at evading their predator and will therefore have more progeny.

5)

If the green allele were to be lost from the population, the beetle popuation would decline upon the invasion of the moss, since the beetles would be easier to spot for the birds, and there would be no Green beetles surviving, that could revive the population.

Genetic diversity is imporant as it allows a species to overcome selection against a particular trait. When negative selection against a particular trait occurs, this can result in a decline of the total population as well is there is not alternate allele that is not under negative selection.