Kaplan Nursing Entrance Practice Exam

What occurs during transcription in the central dogma?

1. RNA is synthesized from a DNA template

2. Amino acids are assembled into proteins

3. DNA duplicates its genetic material

4. Protein is transported from the nucleus

The correct answer is: RNA is synthesized from a DNA template

Transcription is a key process in the central dogma of molecular biology, which describes the flow of genetic information from DNA to RNA to protein. During transcription, RNA is synthesized from a DNA template. This process begins when RNA polymerase, an enzyme, binds to a specific region on the DNA called the promoter. The enzyme unwinds the DNA strands and synthesizes a single strand of messenger RNA (mRNA) by using one of the DNA strands as a template. This mRNA strand carries the genetic information originally encoded in the DNA and is complementary to the DNA template strand. The resulting RNA molecule is then processed and can exit the nucleus to be translated into protein. This describes the fundamental role of transcription in gene expression, as it is the first step that enables the genetic code to be expressed as a functional product. The other choices involve different processes: assembling amino acids into proteins refers to translation, DNA duplication is related to DNA replication, and protein transport relates to the movement of proteins post-synthesis. Thus, the synthesis of RNA from a DNA template characterizes transcription accurately within the context of the central dogma.