PracticeTest1key - PCB3063 Practice Test 1 KEY we are...

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PCB3063 Practice Test 1 1 KEY – we are providing examples of answers here. In general, we look for specific words (underlined here), but it is important to realize that we will also be looking to make sure the terms are explained correctly. If you simply write the word but it is unclear that you know the word means, you will get partial credit at most. If you write the word but it is clear you do not understand the word, you will not get credit. By understand the word, we mean understand how it answers the question, not simply understand the dictionary definition. Finally, if you do not write a word but it is clear from what you wrote that you understand the process we are asking about, you will get at least partial credit. 1) Define the terms complementary and antiparallel with respect to DNA and explain how these terms are relevant to the role that DNA plays in heredity. Complementary – refers to the fact that there is a specific base pairing relationship between the DNA strands. Specifically, the base A pairs specifically with T and the base G pairs specifically with C. Antiparallel – refers the directionality of the sugar-phosphate backbones (5’ to 3’ orientation of the sugars). When DNA is double stranded the strands go in the opposite direction. Because DNA is complementary, each strand has all of the information in the double stranded DNA. This means one can easily copy the DNA by separating the strands and synthesizing a new complementary strand. 2) Describe at least three characteristics that are desirable for model organisms. Based upon the characteristics that you list, compare Zea mays (maize) to another model system such as Arabidopsis thaliana or Neurospora crassa (in other words, one organism you compare has to be maize, but the second can be any model organism you heard about in class). Identify the major group of organisms for each of the models systems you describe (i.e., plant, fungus, animal). Describe both benefits and drawbacks of maize relative to the other model system you describe? Provide at least one most reason that geneticists still use maize? There are general features of model organisms used in genetics – they tend to be small , have a short generation time , have many progeny , have a lot of background information (prior work using that organism), and be easy to grow . Maize does not conform to these characteristics (with the exception of having a lot of background information), but good reasons for geneticists to use maize would be that it is commercially important.
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PCB3063 Practice Test 1 2 3) Here is the biosynthetic pathway for purine nucleotides. Note that a single gene may act in more than one position (e.g. ade 13). Also assume that the ability to synthesize both adenine monophosphate (AMP) and guanine monophosphate (GMP) is necessary for viability and growth and also assume that cells can take up any compound you add to the medium. Inosinate
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This note was uploaded on 04/17/2008 for the course PCB 3063 taught by Professor Marta during the Spring '08 term at University of Florida.

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PracticeTest1key - PCB3063 Practice Test 1 KEY we are...

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