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Introductory textbooks will not get into the details of the lac operon. Basically, the operon is expressed constitutively at a low level that means that Beta Galactosidase and Lactose Permease are expressed at low levels by the bacterium. This is because it takes a little bit of time to build up the concentration of LacI in the cell before it can start to ...


Isothermal DNA amplification technologies have been developed. You do not need thermal cycling to amplify DNA fragments by this method. http://www.ncbi.nlm.nih.gov/pubmed/17720718


Edited after clarifications in question, Let's start with normal functions of both enzymes. Helicases separates DNA strands while polymerase synthesize DNA strands as shown in the following figure. (Image Source: Wikimedia Commons) Watch this animation, it will clear your doubts about function. However, RNA polymerase does have both activities. In ...


DNA mutations arise from either replication errors or the effect of mutagens. Cell division can go into what is known as the G0 phase where division is put on hold. This state is also referred to as a quiescent state (see the related genes here), which is distinct from senescent states where damaged cells are prevented from replicating by, for example, the ...


Don't think about mutagenized animals, think about mutagenized genomes. Depending on when the mutagenesis is carried out, and how efficient it is, a very small number of males could give rise to thousands of mutagenized F1 progeny, each carrying a uniquely mutagenized genome. That is the number to focus on. Typically, in fruit flies and soil nematodes the ...


If what you trying to get is 1kbp of repetitive 150bp sequences, then synthesis as a large chunk might be better idea. It costs ~150-300$ but will potentially save tons of time. (see gBlock from IDT in US) PCR and ligation with repetitive sequences is pain the butt. It might be true that you save money, but time and frustration could be more expensive.


The DNA sequence of the promoter will not change. What transcription factors and co-factors that occupy the promoter may change. In addition, the treatment may cause epigenetic changes at the promoter with regard to methylation and histone modifications that allow for increased DNA accessibility by RNA polymerase. This sounds like it may be a homework ...

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