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The devil is in the details, and therefore we cannot just state that we have understood X% of the DNA. We know e.g. that 2% of the human DNA encode proteins. And for a good number of proteins we know what they do. So you might know that a particular codon AGT encodes a serine residue in a protein, which could have a catalytic activity. Or it has a structural ...


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I think any discussion of this question can benefit from a historical perspective. For a long time, it was in fact believed that proteins was the hereditary material. The Nature Scitable page on the discovery of DNA (1) starts with the following passage: In the first half of the twentieth century, Gregor Mendel's principles of genetic inheritance ...


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For example, a sperm swims faster if it's carrying the genetic material that would result in a tall person and in the comments It seems to me that there would have to be some defined standard of a normal DNA that the sperm would check against to determine how "broken" it is, and I doubt there's something like that If some aspects of sperm ...


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Shigeta, you have some good points there. I wanted to clarify some things. Sperm and ova are considered tissues, not individual living creatures. They are not individually capable of cell division nor production of offspring. They are specialized cells with specific functions that are created by a multicellular organism as a means of transferring DNA. ...


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I think there is a strong driving force for sperm to be free living haploid versions of human beings. Since they are a product of meiosis sperm are the product of recombination of both the male chromosome sets. While I'm sure that if we look closely enough, the germline cells that produce the sperm are contributing some protein and structure to the sperm, ...


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I think the key work here is 'evolve'. Overall GC/AT ratios change by mutations, whose rate is constant. The probability that given a mutation event that one base will be substituted by another one has been modeled in several ways where the probabilities of different mutations may or may not be the same. Overall the GC content will tend to close to 50%. ...


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This kind of thing is normally calculated using the $K_{a}/K_{s}$ ratio, the ratio of synonymous to non-synonymous substitutions. It is not enough to count mutations for coding sequences, you should also take into account whether or not that mutation will actually change the resulting product. There are various online tools that can help you do this, for ...


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The more bases there are per codon the more information you can code for. There are only 22 different amino acids, in consequence we need minimum 3 bases per codon. 1 base-codon --> 4^1 = 4 possible codes which are: A / T / C / G 2 base-codon --> 4^2 = 16 possible codes which are: AA / AT / AC / AG / TT / TA / TC / TG / CC / CA / CG / CT / GG / GC / GT ...


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Yes, Ethanol can precipitate proteins during a DNA precipitation as well, although Acetone will be more efficient. Usually you do a proteinase K digest or a proteinase K digest followed by a Phenol/Chloroform extraction to avoid this problem. I was usually doing the later, I can post my protocol if you are interested.


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A proteinase eg.proteinase K is usually added when extracting dna.


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The writers of the show may have been somewhat imprecise either by accident or intentionally to avoid excessive details. There are several different stages of egg cells, with distinct names for each and for the process that leads from one to the next. The whole process of egg cell creation is called [Oogenesis].1 To quote Wikipedia: Oogenesis starts ...


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I would assume that the labeling occurs in the reduction of NTPs to form dNTPS. This process (catalyzed by ribonucleotide reductase) involves protonating the hydroxyl group on the 2' carbon, allowing it to leave as water, and then adding a hydride to the newly formed carbocation. The two hydrogen atoms (the proton and the hydride) come from two thiols on ...


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It works pretty well and can be used to desalt DNA. The DNA runs a bit different than proteins since it is more a long stretched molecule while a lot of proteins are globular. See this references (the first is about the behaviour of DNA on superose): Size-exclusion chromatography of DNA restriction fragments. Fragment length determinations and a comparison ...


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This is speculation, as I haven't done or read of the required experiment. However, I imagine that this would not be a problem. You're right that the RNA template (TERC) would not hybridize with a poly-G sequence, and so the telomerase would not be able to add more telomere repeats. You can imagine that the poly-G sequence is a cap, preventing telomerase ...


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You can run your DNA sample on agarose gel to see, whether you have significant degradation. If you are interested in contamination, you can make a standard photometric analysis to assess the 260/280 and 260/230 ratios and absorbance at 320 nm on NanoDrop or even something similar to Eppendorf's BioPhotometer. In case RNA may be an obstacle for some ...


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Obviously, it is conceivable that DNA could be so damaged that the organism dies. Trivially, blasting cells with radiation will cause rampant DNA damage, which will trigger p53 and lead to the cells suiciding (apoptosis), this is a "deliberate" (so to speak) mechanism to manage cancer risk. In practice, the reason DNA damage leads to death is usually not ...


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It is important for organisms to be renewed. These organisms have less wear and tear, they are modified through evolution to better fit the current environment, they are more likely to have healthy offspring that they can look after. It must also be considered that genetically we must be optimal in anyway that confers our continued survival as a species. So ...


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Perhaps the best type of study to examine the role of genes (DNA) in human aging are twin studies. They have either: the same DNA (monozygotic, one egg, "identical" twins (MZ) ) or similar DNA (dizygotic twins, two eggs (DZ) ) and are perhaps exposed the same, or different environments. I won't repeat the information in the link, above, but studies of ...


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I'll just extend terdon's answer into more concrete terms. An example of a gene that is constantly read would probably be the one that determines hair colour. If you were able wave a wand over the head of someone with blonde hair, replacing all their DNA with a different version of the gene, say, the one for brown hair, then chances are that as their hair ...


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It means that the direction in which the normal double-strand is wound up (which is also helical) and the direction on which the double helix itself is twited to reach the supercoils are opposite to each other. Have a look at this image from the Wikipedia, I think it makes this clearer: The first show a DNA ring with the normal helix-coiling. The second ...


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From how I read your question, you're wondering if there is some technology to somehow isolate oncogenic proteins inside the cell so they don't do harm, is that correct? The answer is somewhat complicated, as it depends on the protein. First, though, you need to understand that cancer is a very complex disease, and cancer is not caused by a single mutation ...


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The classic analogy here is that of a blueprint. For example this one I found here which is kind of relevant:                                If you use the blueprint above to make yourself a little sister and ...


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The lipopolysaccharide layer of the Gram-negative bacterial cell wall is stabilised by divalent cations. Most recipes for disrupting E. coli cells include Tris-EDTA for this reason. I seem to just know this, so no reference at the moment. All nucleases require Mg2+, which is why there is EDTA in the stop buffer added to restriction digests. Carry-over of ...


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A lot of enzymes need metal ion in their active center (it is actually the metal ion which is taking part in the catalyzed reaction). These are manganese, magnesium, copper and so on. For DNAses the metal in the active center is magnesium and EDTA simply chelates this ions, making them unavailable for the enzyme and thus hinders the enzyme from working. ...


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What you are asking about is the precipitation of DNA (or any other nucleic acid) by isopropanol (or ethanol, which is more common). To do so, you add salt (usually slightly acidic sodium acetate) which makes sure that the phosphate backbone of the DNA is saturated with sodium ions to make it less soluble. Then you add the organic solvent, which precipitates ...



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