rishta
Forum Newbie
Topics: 2
Posts: 21
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hey ppl...
someone plz b nice enof and help me wid conjugation,transduction(generalized,specialized and about lysogeny) and transformation.
i kinda have a basic concept of what is what...but everytime i face a question in any of these topics...i neva get them right,..cant figure out how to solve the questions cuz something is wrong wid my concepts n application in these 3 topics...PLZ HELP!
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| drgho
Forum Junior
Topics: 1
Posts: 115
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All three are the processes to acquire DNA mainly in prokaryotes(bacteria).
Cojugation is the transfer of plasmid or chromosomal DNA from one cell to another through "sex pilus".
Transduction is through virus("bacteriophage" between bacteria) and it can be generalised or specialised depending on the types of phages whether it is virulent phage(undergoing lytic cycle) or temperate phages( undergoing lysogenic cycle).
Virulent phage undergoes lytic cycle in which the phage replicates its DNA immediately after the penetration of bacteria. It then expresses and replicates its own DNA while repressing the expression of bacterial DNA and subsequently destroying bacterial DNA . But some bacteria DNA pieces(anywhere and generalised) may be left intact and it incoporates into the capsid of the phage and transfer to another bacteria.
In specialised transduction, temperate phage incorporates its DNA into the bacterial genome and becomes dormant called prophage. When conditions are right, the phage start to replicate its own DNA and can cause bacteria DNA near to insertion site being replicated and transfered as part of phage genome. So only genes near the site of insertion can be transferred ( specialised ). the process is called phage is undergoing lysogenic cycle and and bacteria acquire new DNA through lysogenic conversion as in diphtheria.
Transformation is the picking up of pure DNA without involvement of sex pilus or phage. Transformation usually occurs in enteric bacteria.
hope this helps a little.
Edited by drgho on 08/18/07 - 03:37 AM
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| rishta
Forum Newbie
Topics: 2
Posts: 21
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hey ..thanx drgho
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