Chapter 12, Problem 15A

Summary Introduction

Introduction:

The process of the synthesis of a new strand of DNA is called DNA replication.

DNA replication is a semiconservative method in which parental DNA separates and serves as templates to produce two daughter DNA. Enzymes such as DNA helicase, RNA primase, DNA polymerase, and DNA ligase are involved in DNA replication.

Answer to Problem 15A

Correct answer:

The correct answer is option (A) RNA primer.

Explanation of Solution

Explanation/justification for the correct answer:

After unwinding of a double strand of DNA, enzyme DNA primase add a short segment of RNA called an RNA primer on each DNA strand. This RNA primer act as a starting point for new DNA synthesis and DNA polymerase begins the addition of appropriate nucleotides to the new DNA strand.

Explanation for incorrect answer:

Option (B) Nucleotide unit: Nucleotide units are added to the 3’ end of RNA primer in the new strand.

Option (C) messenger RNA: mRNA synthesized from the DNA by the Transcription process.

Option (D) transfer RNA: In the Translation process, tRNA acts as the interpreters of the mRNA codon sequence.