Final answer:
The alpha and beta subunits of the insulin receptor are encoded by the same DNA, specifically the INSR gene. This reflects the sophisticated use of genetic information to produce complex protein structures necessary for cellular function.
Step-by-step explanation:
The student's question relates to which two subunits are encoded by the same DNA. Based on the information provided, it seems that the alpha and beta subunits of the insulin receptor are encoded by a single gene (INSR). The insulin receptor is critical for cellular communication and metabolic regulation, and the gene that encodes it reflects important aspects of genetic organization and protein structure. The two subunits have distinct functional roles, with the alpha subunits being extracellular and the beta subunits spanning the cellular membrane and participating in signal transduction upon insulin binding.
The concept of a single gene encoding multiple protein subunits is an important one in molecular biology, as it demonstrates the efficiency of the genetic code and the complexity of protein assembly. This is further exemplified in the provided details regarding RNA polymerases in E. coli, which consist of multiple subunits including two identical alpha subunits, all of which are essential for the transcription process.
Overall, the answer to the student's question is that the alpha and beta subunits of the insulin receptor are encoded by the same DNA, specifically the INSR gene.