What does the central dogma of molecular biology explain?

The central dogma of molecular biology explains the flow of genetic information within a biological system, specifically through the processes of transcription and translation. It describes how genetic information encoded in DNA is first transcribed into messenger RNA (mRNA) and then translated into a protein, which ultimately serves various functions within the cell. This framework is fundamental to understanding how genes express themselves and how proteins are synthesized, which are crucial for the functioning and regulation of biological organisms.

The other options do not accurately represent the central dogma; for instance, while DNA replication is an essential process in genetics, it does not encompass the broader scope of gene expression as outlined in the central dogma. Additionally, the structure of the cell membrane and the classification of living organisms are separate topics that do not pertain to the flow of genetic information, further demonstrating the specificity of the central dogma.