Cockayne syndrome is a rare genetic disorder caused by a mutation in the ERCC6 gene. It is inherited as an autosomal recessive disease. The condition affects three in every million newborn babies. What is the frequency of the mutation in the general population?

Evolution and Ecology 4 Long Questions in the file, please show your work and avoid plagiarism. Please and thank you

Requirements: answer/work

BIOS 230, Summer 2018

Homework 1

Due by end of day, Sept 6 (5 pts. Each)

1. Cockayne syndrome is a rare genetic disorder caused by a mutation in the ERCC6 gene. It is inherited as an autosomal recessive disease. The condition affects three in every million newborn babies. What is the frequency of the mutation in the general population? In a population of 150,000 people, how many are expected to be carriers (heterozygous) for this disease? Show your work. Briefly, what are the signs and symptoms of this disorder? Show your work.

2. In the plant called Indian paintbrush, the allele for red flower color (R) is dominant over the allele for white flower color (r). We sample a population and find 600 plants have white flowers and 216 have red flowers. If the population is in HWE, what are the allele frequencies of R and r in this population? How many of the plants that have red flowers are homozygous and how many are heterozygous at the flower color locus? Show your work and round allele frequencies to two decimal places.

3. You notice that there are a lot of black (melanistic) squirrels in your town. You speak to a zoologist who tells you that in squirrels, coat color is controlled by a single gene with two alleles (B1 & B2) that are co-dominant. B1B1 individuals are black, B1B2 individuals are brown, and B2B2 are tan. You survey the population in your town and find 120 black squirrels, 51 brown squirrels, and 23 tan squirrels. Based on the results of your χ2 test, is this population in HWE for coat color? If not, what might explain this pattern (based on your comparison of observed and expected values)? Make sure to show your work.

4. Insects can also be melanistic. The classic case of industrial melanism was reported in moths of the species Biston betularia. Industrial melanisms refers to the dark pigmentation that evolved in some insects giving them protective coloration on soot covered vegetation in heavily industrialized areas prior to air pollution regulation. In a heavily polluted area near Birmingham, England in 1956, 82% of the moths were black due to the presence of a dominant gene for melanism, and the rest were white. Estimate both the frequency of the dominant allele in this population, and the proportion of black moths that are heterozygous. Show your work.

5. The CCR5-del32 deletion refers to a mutation on the CCR5 gene that codes for a protein on the surface of white blood cells. Individuals with this mutation are resistant to HIV-1 infection. You were interested in the population genetics of this mutation in Finland. You tested 584 Finnish people and found that 442 were +/+, 130 were +/del32, and 12 were del32/del32. Are the observed data significantly different from HWE? Depending on your answer, suggest a hypothesis for why it is or is not in HWE. Show your work.