Final answer:
The incorrect statement about genes is that D.all genes encode mRNAs which are translated into protein; some genes code for non-coding RNA molecules with various functions within the cell.
Step-by-step explanation:
The statement that is not true about genes is: D) all genes encode mRNAs, which are translated into protein. While most genes do encode mRNAs that are subsequently translated into proteins, not all genes perform this function. Some genes code for stable RNA molecules that are not translated into proteins, such as ribosomal RNA (rRNA), transfer RNA (tRNA), and other non-coding RNAs. These RNA molecules play crucial roles in processes such as protein synthesis and gene regulation. Moreover, the presence of introns and exons within eukaryotic genes adds a layer of complexity, where introns are removed during mRNA processing and thus do not encode functional proteins.
In eukaryotic cells, genes are located on chromosomes within the nucleus. DNA sequences, organized into genes, are responsible for coding RNA and protein molecules that are essential for all cellular processes. The regulation of gene expression is critical for cell function, and the deployment of specific genes to produce proteins is highly regulated and situational within different cell types.