Describe how a molecule of mRNA is made during transcription.

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Transcription is the process by which RNA is made from DNA. The RNA that is made during transcription will be used later during translation. During translation, the RNA's code will be used to make proteins. There are three main stages of transcription: initiation, elongation, and termination. These three stages are...

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Transcription is the process by which RNA is made from DNA. The RNA that is made during transcription will be used later during translation. During translation, the RNA's code will be used to make proteins. There are three main stages of transcription: initiation, elongation, and termination. These three stages are explained below. 

The first stage of transcription is initiation. During initiation, RNA polymerase binds to a specific set of nucleotides on the DNA called the promoter. The RNA polymerase then begins to unwind the DNA. 

The second stage of transcription is elongation. During elongation, only one of DNA's strands serves as a template. RNA polymerase joins free nucleotides (specifically, ribonucleotides triphosphates) to their complementary bases on the DNA template in order to form an mRNA strand. RNA is made in the 5' to 3' direction. As the RNA polymerase moves down the DNA template, the DNA rewinds to form a double helix. 

The final stage of transcription is termination. Elongation continues until the RNA polymerase reaches the terminator, which is a sequence of nucleotides that signals the end of transcription. The termination sequence usually transcribes for an adenine tail and a nucleotide palindrome. At this point, the mRNA is released from the DNA template strand. 

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