Definition:                 "Copying of information from DNA to RNA which exit nucleus is                                                         known as transcription"
Explanation:                    Transcription is a vital process for living organisms, because it is a staring point for protein synthesis. It occurs inside the nucleus and is carried out by RNA polymerase enzyme. In eukaryotes RNA pol is of three types: these are RNA Pol 1, RNA Pol 2, and RNA Pol 3. In prokaryotes it is of only one type.
Steps in transcription:                                     Transcription consists of three main steps
1. Initiation:                   In this step RNA pol attach to DNA template at 5 prime end in the promoter region to start the formation of complementary strand of RNA.  In prokaryotes there is a region called
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Pribnow box, with the </span>consensus sequence<span> TATAAT present about 10 base pair away from site that serves as a transcription initiation. In eukaryotes the promoter region is more complex it contain activator and enhancer.
2. Strand elongation:                                   </span><span>Once transcription is initiated, the DNA double helix unwinds and RNA polymerase reads the template strand, adding nucleotides to the 3′ end of the growing chain.
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3. Transcription Termination:
                                                Terminator sequences are found close to the ends of non-coding sequences. Before termination polyadenylation occurs.  <span>
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