During DNA replication, a DNA polymerase synthesises a complementary strand. If the template strand contains 30 nucleotides, how many phosphodiester bonds are formed in the new strand?
Answer
29
The correct answer is 29 — With 30 nucleotides, phosphodiester bonds are formed.
Step-by-step solution
- Each addition of a nucleotide to the growing strand creates one phosphodiester bond between the 5′‑phosphate of the incoming nucleotide and the 3′‑hydroxyl of the last nucleotide.
- The number of bonds equals the number of nucleotides added minus one.
- With 30 nucleotides, phosphodiester bonds are formed.
Common mistake: Counting 30 bonds instead of 29
Concept tested: Phosphodiester bond formation in nucleic acids
Published · How this solution was prepared and checked
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