BS 161 FINAL EXAM WITH COMPLETE SOLUTIONS ( 3 VERSIONS)

BS 161 FINAL EXAM WITH COMPLETE SOLUTIONS ( 3 VERSIONS) VERSION 1 Barbara McClintock, who achieved fame for discovering that genes could move within genomes, had her meticulous work ignored for nearly four decades, but eventually won the Nobel Prize. Why was her work so distrusted? A)She worked only with maize, which was considered "merely" a plant. B)Geneticists did not want to lose their cherished notions of DNA stability. C)She allowed no one else to duplicate her work. D)The work of women scientists was still not allowed to be published. E)There were too many alternative explanations for transposition. - B Which of the following is a representation of gene density? A)Humans have ~20,000 genes in 2,900 Mb. B)C. elegans has ~20,000 genes. C)Fritillaria has a genome 40 times the size of a human. D)Humans have 27,000 bp in introns. E)Humans have 2,900 Mb per genome. - A If humans have 2,900 Mb, a specific member of the lily family has 120,000 Mb, and a yeast has ~13 Mb, why can't this data allow us to order their evolutionary significance? A)Size is mostly due to "junk" DNA. B)Size does not vary with gene complexity. C)Size does not compare to gene density. D)Size is comparable only within phyla. E)Size matters less than gene density. - B Fragments of DNA have been extracted from the remnants of extinct woolly mammoths, amplified, and sequenced. These can now be used to A)appreciate the reasons why mammoths went extinct. B)introduce into relatives, such as elephants, certain mammoth traits. C)clone live woolly mammoths. D)study the relationships among woolly mammoths and other wool-producers. E)understand the evolutionary relationships among members of related taxa - E Why is it unwise to try to relate an organism's complexity with its size or number of cells? A)A very large organism may be composed of very few cells or very few cell types. B)A simple organism can have a much larger genome. C)A single-celled organism, such as a bacterium or a protist, still has to conduct all the complex life functions of a large multicellular organism. D)A complex organism can have a very small and simple genome. E)A single-celled organism that is also eukaryotic, such as a yeast, still reproduces mitotically. - C What is metagenomics? A)genomics as applied to an entire phylum B)genomics as applied to a species that most typifies the average phenotype of its genus C)the sequencing of only the most highly conserved genes in a lineage D)sequencing DNA from a group of species from the same ecosystem E)the sequence of one or two representative genes from several species - D Which of the following most correctly describes a shotgun technique for sequencing a genome? A)physical mapping followed immediately by sequencing B)cloning large genome fragments into very large vectors such as YACs, followed by sequencing C)cloning the whole genome directly, from one end to the other D)cloning several sizes of fragments into various size vectors, ordering the clones, and then sequencing them E)genetic mapping followed immediately by sequencing - D What is the difference between a linkage map and a physical map? A)For a physical map, the ATCG order and sequence must be achieved; however, it does not for the linkage map. B)For a linkage map, it is shown how each gene is linked to every other gene. C)For a physical map, the distances must be calculable in units such as nanometers. D)For a linkage map, markers are spaced by recombination frequency, whereas for a physical map they are spaced by numbers of base pairs (bp). E)There is no difference between the two except in the type of pictorial representation. - D In large scale, genome-wide association studies in humans, correlation is sought between A)single nucleotide polymorphisms found in families with a particular introns sequence. B)lengthy sequences that might be shared by most members of a population. C)large inversions that displace the centromere. D)single nucleotide polymorphisms found only in persons with a particular disorder. E)single nucleotide polymorphisms in two or more adjacent genes. - D Which of the following modifications is least likely to alter the rate at which a DNA fragment moves through a gel during electrophoresis? A)methylating the cytosine bases within the DNA fragment B)altering the nucleotide sequence of the DNA fragment C)increasing the length of the DNA fragment D)neutralizing the negative charges within the DNA fragment E)decreasing the length of the DNA fragment - B In yeast signal transduction, the yeast cells A)secrete molecules that result in response by other yeast cells. B)must physically and directly interact. C)produce signal molecules that change themselves so they can interact with one another. D)produce response molecules that diffuse to other yeast cells. E)mate, after which the new cells secrete hybrid signals. - A Which of the following is true for the signaling system in an animal cell that lacks the ability to produce GTP? A)It would employ a transduction pathway directly from an external messenger. B)It could activate only the epinephrine system. C)It would not be able to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane