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Unformatted text preview: on. ________________________ Part three of the exam is on the next page Page 4 of 5 BIO1130 Midterm Examination – November 13, 2010 STUDENT NUMBER:_______________________________ Don’t enter your name. 12 pts Part 3: Answer the following two questions in the space provided. What are the Protostomia and what are the major events in the evolution of this animal taxon? 3points for Protostome characters {Mesoderm and body cavity from schizocoely/mesoderm block arises near blastopore and splits to form cavity}{Spiral cleavage – at eight cell stage top four cells spiral/shift and sit between the bottom four}{Blastopore becomes the mouth/Anus forms opposite the blastopore} If the word shizocoely and spiral cleavage appear without an explanation give only one point as a part mark. There must be an explanation to show that the student knows what the terms means. If it is there then the full two points can be given. 3 points for evolutionary sequence: {colonial coanoflagellate developed tissues,}{three tissue layers – triploblastic}{Bilateral symmetry} What is gene fixation and how does it come about; what are the consequences for a population that experiences it. What is the {Form of Natural selection}{When there is high selective pressure}{against a phenotype or Allele}{Allele/phenotype disappears completely from the population}{Consequence: the remaining allele is fixed and a genetic variant is lost}{example strong selection has resulted in disease/plant/insect resistance to control teatments – flavour in tomatoes/ breeding for packaging and transport resulted in the flavour genes being lost} Page 5 of 5...
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This note was uploaded on 09/02/2012 for the course BIO 1130 taught by Professor Fenwick during the Spring '08 term at University of Ottawa.

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