Which of the following is an important exception to the central dogma of molecular biology? a. Many genes code for RNAs that function directly in the cell. b. DNA is the repository of genetic information in all cells. c. Messenger RNA is a short-lived 'information carrier.' d. Proteins are responsible for most aspects of the phenotype.

The central dogma of molecular biology describes the flow of genetic information within a biological system. It outlines the process where DNA is transcribed into RNA, which is then translated into proteins. This framework is fundamental for understanding how genetic information is expressed and regulated in cells.

While the central dogma emphasizes the role of RNA as a messenger between DNA and proteins, many genes also code for non-coding RNAs that perform essential functions in the cell. These RNAs, such as ribosomal RNA (rRNA) and transfer RNA (tRNA), are crucial for protein synthesis and regulation, highlighting an important exception to the traditional view of RNA's role.

The phenotype of an organism is the observable physical and biochemical characteristics, which result from the expression of its genes. While proteins play a significant role in determining phenotype, the influence of non-coding RNAs and environmental factors also contributes to the complexity of gene expression and phenotypic variation, challenging the simplistic view of the central dogma.