THE MOLECULAR BASIS OF INHERITANCE
DNA MAKES RNA MAKES PROTEIN
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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An entire chromosome
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All of the DNA that is in the nucleus
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An entire gene
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Only a few bases at a time
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Detailed explanation-1: -Transcription is the process of copying a segment of DNA into RNA. The segments of DNA transcribed into RNA molecules that can encode proteins are said to produce messenger RNA (mRNA). Other segments of DNA are copied into RNA molecules called non-coding RNAs (ncRNAs). mRNA comprises only 1–3% of total RNA samples.
Detailed explanation-2: -The resulting mRNA is a single-stranded copy of the gene, which next must be translated into a protein molecule. Figure 1: A gene is expressed through the processes of transcription and translation.
Detailed explanation-3: -In transcription, the DNA sequence of a gene is transcribed (copied out) to make an RNA molecule.
Detailed explanation-4: -Although the mRNA contains the same information, it is not an identical copy of the DNA segment, because its sequence is complementary to the DNA template. Transcription is carried out by an enzyme called RNA polymerase and a number of accessory proteins called transcription factors.
Detailed explanation-5: -RNA polymerase synthesizes an RNA strand complementary to a template DNA strand. It synthesizes the RNA strand in the 5’ to 3’ direction, while reading the template DNA strand in the 3’ to 5’ direction.