1209+Study+Guide+for+Final

# 1209+Study+Guide+for+Final - 1209 Study Guide for Final...

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1209 Study Guide for Final- Gerald George Final will be ~50% practical (diversity labs) and ~50% Evolution and Ecology Part 1: Evolution and Ecology Evolution Evolution: Change in the genetic make-up (allele frequency) of a population over time, Works on the population level over generations Genetic equilibrium- is when there are no changes in allele frequency, no evolution occurs What is required for equilibrium? -population has to be sufficiently large -no gene flow -no mutations occur -random mating- an equal opportunity to mate regardless of genotype, examples of non- random mating, corn, chickens -no natural selection This does not happen in nature-always at least 1 violation Hardy-Weinberg equation p 2 +2pq+q 2 =1 -know how to calculate the homozygous dominant & recessive and heterozygous conditions example: Using the Hardy-Weinberg equation, p 2 + 2pg + q 2 =1 determine the values of p 2 and 2pg in a population of humans that shows the recessive phenotype for Cystic fibrosis in 9% of the population. (hint p + q=1). Q2=.09 so q=.3 and p=.7 .7squared=.49 .49 +2pq + .09=1 2pg=.42 p 2 = _________.49__________ (1pt) 2pq=________.42__________ (1pt) Natural selection: is the evolutionary process by which favorable traits that are heritable become more common in successive generations of a population of reproducing organisms , and unfavorable traits that are heritable become less common . Natural selection acts on the phenotype , or the observable characteristics of an organism, such that individuals with favorable phenotypes are more likely to survive and reproduce than those with less favorable phenotypes. If these phenotypes have a genetic basis, then the genotype associated with the favorable phenotype will increase in frequency in the next generation. Over time, this process can result in adaptations that specialize organisms for particular ecological niches and may eventually result in the emergence of new species (speciation). Results of Pop G simulations: Genetic equilibrium- p at .5 Selection-a slight change in fitness of the homozygous recessive allowed homozygous dominant to become fixed Heterozygote advantage- selection for heterozygote Genetic drift- fixation with different alleles becoming fixed

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-The goal of the bacteria population experiment is to see how gene frequency in a population can change by natural selection. How might bacteria populations change when exposed to an antibiotic?2 Hypothesis 1. That antibiotics are inducing mutations into the bacteria. This allows them to be resistant to antibiotics. So higher anti levels would yield higher mutation rates 2. Antibiotics are selecting for bacteria with resistance to antibiotics out of available genetic diversity To test these hypotheses we will transfer the colonies to 3 levels of the antibiotic tetracycline Null: there will be no difference between treatment levels, antibiotic will not have any effect on the number of surviving colonies Alt 1: Induced mutation hypothesis –expect most in high level
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## This note was uploaded on 11/29/2011 for the course BIOL 1001 taught by Professor Minor during the Fall '08 term at LSU.

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1209+Study+Guide+for+Final - 1209 Study Guide for Final...

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