Question 8 of 25intermediate🔧 ApplyShort Answer2 marks

Can you now write the sequence of RNA transcribed from the above DNA?

Correct Answer

The RNA sequence transcribed from the given DNA is:

5′-UACGUACGUACGUACGUACG-3′

During transcription, the template strand (with 3′–5′ polarity) is used by DNA-dependent RNA polymerase to synthesize RNA in the 5′–3′ direction. The RNA sequence is complementary to the template strand.

Applying the principle of complementarity:

  • Adenine (A) in DNA pairs with Uracil (U) in RNA (instead of Thymine)
  • Thymine (T) pairs with Adenine (A)
  • Guanine (G) pairs with Cytosine (C)
  • Cytosine (C) pairs with Guanine (G)

Thus, the template strand 3′-ATGCATGCATGCATGCATGC-5′ produces the RNA sequence 5′-UACGUACGUACGUACGUACG-3′.

Exercise: In-text Question (Page 14) | Q: 8 | (Page 14)
For More Understanding

Explanation

The textbook provides a hypothetical transcription unit with Template Strand (3′-ATGCATGCATGCATGCATGC-5′) and Coding Strand (5′-TACGTACGTACGTACGTACGTACG-3′). According to the chapter, transcription follows the principle of complementarity where the template strand (3′–5′ polarity) directs RNA synthesis. The key difference from DNA replication is that adenosine pairs with uracil in RNA instead of thymine. The RNA sequence produced is identical to the coding strand but with uracil replacing thymine.

Solution Steps

  1. Step 1: Identify the template strand with 3′–5′ polarity: 3′-ATGCATGCATGCATGCATGC-5′

  2. Step 2: Apply complementarity rules (A→U, T→A, G→C, C→G) to synthesize RNA

  3. Step 3: Write RNA sequence in 5′–3′ direction: 5′-UACGUACGUACGUACGUACG-3′

PreviousNext