These two loci are independent and located on

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Unformatted text preview: will become a fish that lives in a lake represented by the lab. There should be around 15‐20 fish in the lake. A 75 Lab4 ‐ Microevolution genotype will be assigned to each fish living in the lake. This genotype is represented by coloured cards corresponding to the different loci of which we will follow the transmission: the Blue locus and the Green locus. These two loci are independent and located on distinct chromosomes. Each of these loci possesses two allele types: Dark and Light. In addition to the Blue and Green loci, each fish has a mating type (either XX or XY) represented by white coloured cards. When you start the lab today, you’ll be assigned a fish with a genotype. Then your fish will exchange genes with other fish in the class and will produce offspring. Then again, the offspring will produce its own offspring. This way you will study the genetics of the fish population and observe the genetic variations that may occur and lead to the evolution of your population. 1‐ Characterization of the population: It’s time to meet the fish you will be for the first exercise. As mentioned before, its genotype is characterized by three features: The blue locus (dark: B or light: b alleles) controlling the shape of the fin. The green locus (dark: G or light: g alleles) controlling the size of the mouth. The mating type (white cards): XX or XY. Individuals can only exchange genes with individuals of the other mating type. Your TA will write on the black board the genotypic composition of the population, from which you will calculate the frequencies. Your task is to follow step‐by‐step instructions and answer questions on the provided questionnaire. You should exchange ideas and comments with the other students and your TA. Answer Questions 1‐6. 2‐ Hardy‐Weinberg proportions: Since you know the frequencies of each allele present in the population, you can calculate the expected genotypes frequencies using the HW principle. Answer Questions 7‐10. 3‐ Genetic drift Before you start to create new generations of fish, consider these questions: ‐ Do allele frequencies change from one generation to another? ‐ Do genotype frequencies change from generation to generation? 76 Lab4 ‐ Microevolution Allele exchange procedure: Bring your fish to one of the spawning grounds located at the end of each bench (you will find supplementary allele cards there). You can go to any spawning ground in the lab. Then you must locate another fish with a different mating type than yours. If you can’t find a fish with a compatible mating type, wait out this turn until the second round. Then follow this procedure: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. Write down both parents genotypes in table 3 (you are parent #1). Put the two alleles from the blue locus of your fish in each of your fists. The person representing your mate should blindly pick one of your fists. The allele chosen will be the first allele of the blue locus of the first offspring. Repeat step 2, except this time you will randomly...
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This note was uploaded on 02/04/2014 for the course BIO 1130 taught by Professor Fenwick during the Fall '08 term at University of Ottawa.

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