Problem_Set_1_text_problems_key - Biology 202 Problem Set 1...

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Biology 202 Problem Set 1 1/13/12 This problem set covers material from January 9 th through January 18 th From Griffiths et al. 9 th edition, (# in parentheses = same question found in the10 th edition): Chapter 2, problems 2(16), 3(17), 9(23), 11(25), 13(27) Chapter 3, problems 7(18), 15(26), 16(27) Chapter 7, problems 1(6), 2(7), 3(8), 5(10), 18(24), 19(25), 26(30), 27(31) 2.2(16) PFGE separates DNA molecules by size. When DNA is carefully isolated from Neurospora (which has seven different chromosomes) seven bands should be produced using this technique. Similarly, the pea has seven different chromosomes and will produce seven bands (homologous chromosomes will co-migrate as a single band). 2.3(17) There is a total of 4 m of DNA and nine chromosomes per haploid set. On average, each is 4/9 m long. At metaphase, their average length is 13 μ m, so the average packing ratio is 13 x 10 -6 m: 4.4 x10 -1 or roughly 1:34,000. This remarkable achievement is accomplished through the interaction of the DNA with proteins. At its most basic, eukaryotic DNA is associated with histones in units called nucleosomes and during mitosis, coils into a solenoid. As loops, it associates with and winds into a central core of nonhistone protein called the scaffold. 2.9(23) As cells divide mitotically, each chromosome consists of identical sister chromatids that are separated to form genetically identical daughter cells. Although the second division of meiosis appears to be a similar process, the “sister” chromatids are likely to be different. Recombination during earlier meiotic stages has swapped regions of DNA between sister and nonsister chromosomes such that the two daughter cells of this division typically are not genetically identical. 2.11(25) Yes. It could work but certain DNA repair mechanisms (such as postreplication recombination repair) could not be invoked prior to cell division. There would be just two cells as products of this meiosis, rather than four. 2.13(27) Yes.
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This note was uploaded on 01/24/2012 for the course ENG 101 taught by Professor Richey during the Spring '08 term at N. Colorado.

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Problem_Set_1_text_problems_key - Biology 202 Problem Set 1...

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