Author: Anonymous

The figure below depicts a snapshot of a circular DNA molecule early in the process of theta replication. A replication bubble has opened at the top of the molecule. Various landmarks are labeled around the DNA molecule with capital letters (A through M). Only the parent (template) DNA strands are shown in this diagram! It is your job to infer how and where the new, synthesized DNA strands are being made. You will use the capital letter landmarks (A through M) to indicate *where* the molecules listed below will be located on the parent DNA.   For each item below, fill in the blank with all the letter locations that apply. For example: if helicases are acting in more than one location on the DNA, you must indicate all locations for full points. Points will be deducted for listing incorrect locations, though, so don’t just write every letter in every blank. If you list multiple letters, please separate each of them with a comma. Location(s) where helicase is acting [helicase] Location(s) where topoisomerase is acting [topo] Location(s) where the replisome (DNA polymerase) is acting [replisome] Location(s) where you would find dnaA boxes [dnaA] Location(s) where you would find a termination site [termination] Location(s) where you would find Okazaki fragments [Okazaki] Location(s) where you would find leading strand(s) [leading]

Use this information for the next 2 questions: The amino acids phenylalanine and tryptophan are synthesized from several precursors as diagrammed below. Enzymes (Enz.) A through G are encoded by genes A through G, respectively. Auxotrophic mutants of the mold Neurospora have been identified that cannot make phenylalanine and/or tryptophan due to mutations in a gene (or genes) that encode the enzymes of this pathway. These two amino acids are necessary for life, so they must either be synthesized by the Neurospora cells or provided in the medium on which the yeast are grown. A Neurospora single mutant has been found that can make neither tryptophan nor phenylalanine. In which gene must the mutation be located?

The amino acid sequences shown in the following table were obtained from the central region of a particular polypeptide chain in the wild-type (WT) and several mutant bacterial strains (the whole protein is not shown, just an internal segment of it). Each mutant strain has a point mutation in the gene that produces the polypeptides listed in the table. Each mutant strain depicted contains only one mutation. A blank box indicates no amino acid codon exists in that position.   For each of the mutants, fill in the table below indicating what kind of mutation has occurred: missense, nonsense, synonymous, or frameshift, and in which codon (1-9) the mutation occurred. You do not need to distinguish between conservative and nonconservative missense mutations. Type of mutation Codon where mutation occurred Mutant 1 [answer1] [answer2] Mutant 2 [answer3] [answer4] Mutant 3 [answer5] [answer6] Mutant 4 [answer7] [answer8] Mutant 5 [answer9] [answer10]

Use the data in the table from the last question to infer the probable order of the three genes that are closest together. 

Fill in the table with the appropriate answers from the list. There might be more than one possible correct answer for each box, but you will choose only one answer from the dropdown list for each box. Here’s an example of how to read this table: in row 1, Deaminated cytosine is the type of DNA Damage (column 1), Reactive Oxygen Species is a source of that DNA damage (column 2), and you must fill in the *first* line of defense repair for that damage in the 3rd column.  Answers from the dropdown list may be used once, more than once, or not at all.               DNA Damage Source of DNA Damage First Line of Defense Repair Mechanism Deaminated cytosine Reactive Oxygen Species [answer1] [answer2] UVB radiation [answer3] Abasic site [answer4] [answer5] T-G basepairing Replication [answer6] Double strand break in a non-dividing cell [answer7] [answer8] [answer9] Intercalating agent MMR

You are working with Neurospora, a fungus that generates an ascus with 8 ordered spores. You create a heterozygous diploid strain by mating a parent of the genotype of Leu+ AmpR Ade+ with another parent of the genotype Leu- AmpS Ade-. All 3 of these genes are linked in the order written. Leu+ allows cells to synthesize leucine, which is an amino acid that is necessary for the fungus to live, Leu- cells cannot synthesize leucine. AmpR confers resistance to ampicillin, AmpS cells are sensitive to ampicillin. Ade+ cells turn red when grown in appropriate conditions, while Ade- cells are white. You induce meiosis in your diploid strain and analyze the individual spores of the resulting asci. Among your population of asci, you find one ascus with spores of the phenotypes listed in the table below. The spores are numbered in the order they were positioned in the ascus. Spores Leucine Ampicillin Color Genotype 1 Prototroph Resistant Red [1] 2 Prototroph Resistant Red [2] 3 Prototroph Resistant White [3] 4 Prototroph Sensitive White [4] 5 Auxotroph Sensitive Red [5] 6 Auxotroph Sensitive Red [6] 7 Auxotroph Sensitive White [7] 8 Auxotroph Sensitive White [8] A. Write the full genotype of each spore into the genotype column of the table. Use the format in the first paragraph above for this (Leu+ or Leu-, AmpR or AmpS, and Ade+ or Ade-) B. What is the aberrant spore genotype ratio in this ascus? [ratio] (please indicate both the ratio and the gene affected) C. Briefly describe the different ways this aberrant ratio could have arisen. You only need to include 2 things here: –what kind(s) of heteroduplex(es) were possible –how the heteroduplex(es) were repaired and what they were repaired to, if at all  [how]

IN YOU OWN WORDS, outline the four steps of muscle contraction.  Name the steps and include the major events.

This term refers to a muscle’s ability to shorten forcefully.

The first thing that must happen for a contraction to stop after the axon terminal has released ACh  is:

This muscle fiber type uses oxygen and the enzyme that cleaves ATP is slow-acting.