2010 final exam key

2010 final exam key - 2010 BICD100 Final Exam KEY NAME_ PID...

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1 2010 BICD100 Final Exam KEY NAME_________________________________________ PID ____________________________ 1) . Genes are transferred from four different E. coli Hfr strains to an F - recipient in the order indicated in this table. Draw a map showing the relative positions of these genes on the circular E. coli chromosome. Also indicate the sites of F plasmid integration with arrows showing the direction of transfer (show all four F insertions on one circular map with all the genes on it) (20 pts). The following information is background for questions 2 and 3 (pgs. 2-5): Stickleback fish have been the subject of many population and evolutionary genetic studies because of the morphological variation within and among different populations around the world, many of which used to be considered different species because they look so different. Their Latin name, Gasterosteus aculeatus, means “bony stomach with spines”, referring to lateral and pelvic skeletal structures usually present in marine (ocean- dwelling) stickleback populations. As illustrated below in fish that have been fixed and stained to highlight their bones, this includes lateral plates on the flanks of the fish’s body and a pair of pelvic spines, which are supported by a pelvic girdle attached to the lateral plates by ascending branches. Presumably, this “skeletal armor” makes sticklebacks a less rewarding food source for their predators than they would otherwise be. Freshwater populations of sticklebacks are also found worldwide. They are established when marine sticklebacks swim up rivers to colonize inland lakes. Most freshwater sticklebacks have also skeletal armor, but some do not, such as the one illustrated below that almost entirely lacks lateral plates and a pelvic girdle, and completely lacks pelvic spines and ascending branches.
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2 2). In a study published in Proceedings of the National Academy of Sciences USA in 2004, a group of scientists analyzed the genetic basis of skeletal armor loss in sticklebacks collected from three different Alaskan lakes where all the sticklebacks lack lateral plates. These populations are assumed to have arisen independently from marine ancestors because the lakes are far apart and each is surrounded by many other lakes containing fully armored sticklebacks. Fish lacking lateral plates from each lake population were crossed with Alaskan marine sticklebacks with lateral plates, giving the following results (F 2 populations were generated by intercrossing the F 1 ): Cross F 1 progeny F 2 progeny Bear Paw Lake X marine All 50 had lateral plates 358 had lateral plates, 123 did not Boot Lake X marine All 33 had lateral plates 276 had lateral plates, 99 did not Whale Lake X marine All 42 had lateral plates 274 had lateral plates, 88 did not a. Which of the following conclusions is best supported by these results (6 pts)? i. Lack of lateral plates in all 3 lake populations is due to a dominant mutation in a single gene
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This note was uploaded on 08/19/2010 for the course BICD bicd 100 taught by Professor Soowal during the Winter '08 term at UCSD.

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2010 final exam key - 2010 BICD100 Final Exam KEY NAME_ PID...

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