Question

6. You are interested in studying a species of Jacaranda mimisofolia, a flowering tree that is found throughout southern California. You sequence the gene GAPDH in 300 plants, and obtain the following genotypic counts:

GG: 45 plants

Gg: 60 plants

a. What are the genotypic and allelic frequencies in this population? Show your work.

b. Is this population in Hardy-Weinberg Equilibrium? If you cannot tell, you can write this and explain. Show your work and explain.

c. You return to this population a long, long time from now, and sequence the same gene again. You find three alleles this time. What could explain the addition of a third type of allele? Explain, and discuss all possibilities (if more than one exists).

Answer 1

a.

Page No. aut us plants Giver - tolal planetos 1 300 Gg. 60 plants Total - Chatly JF 193 farbyte frequency L gg Genety be frequency Allell xag q=1 - 1-0.25 z 0.75 p = 24h tl 8n = 2 XY5tGo 2x3 os 0.25

b. If a population is in a state called Hardy-Weinberg equilibrium, the frequencies of alleles, or gene versions, and genotypes, or sets of alleles, in that population will stay the same over generations (and will also satisfy the Hardy-Weinberg equation).  If the allele frequencies are the same for both generations then the population is in Hardy-Weinberg Equilibrium. And also p + q = 1 in hardy weinberg equilibrium.

c. Genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism’s offspring). Variation allows some individuals within a population to adapt to the changing environment. Because natural selection acts directly only on phenotypes, more genetic variation within a population usually enables more phenotypic variation. Some new alleles increase an organism’s ability to survive and reproduce, which then ensures the survival of the allele in the population.