Comprehension

Read the following passage and answer the questions that follow:
The process of copying genetic information from template strand of DNA into RNA is called transcription. It is mediated by RNA polymerase. Transcription takes place in the nucleus of eukaryotic cells. In transcription, only a segment of DNA and only one of the strands is copied into RNA.

Question: 1

Why is the strand of DNA with 3’ → 5’ polarity transcribed and not the other strand of 5’ → 3’ polarity?

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RNA polymerase reads the template strand in the 3’ → 5’ direction to synthesize RNA in the 5’ → 3’ direction, ensuring accurate genetic information transfer.

Updated On: Mar 29, 2026

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Question: 2

Why is hnRNA required to undergo splicing?

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hnRNA must undergo splicing to remove non-coding introns and form a mature mRNA molecule ready for translation.

Updated On: Mar 29, 2026

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Question: 3

Mention the two additional processes which hnRNA needs to undergo after splicing to become functional.

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After splicing, hnRNA undergoes capping and polyadenylation to become functional mRNA capable of translation.

Updated On: Mar 29, 2026

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Question: 4

Why is only one strand of the DNA transcribed? Give two reasons.

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Only one DNA strand is transcribed because RNA polymerase uses the 3’ → 5’ oriented strand as a template to synthesize the RNA in the 5’ → 3’ direction.

Updated On: Mar 29, 2026

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