Genes, as sequences of DNA, dictate the sequence of amino acids in proteins, which in turn determine the proteins' shape and function. The process begins with transcription, where DNA is read to produce mRNA, followed by translation, where mRNA is converted into proteins. These proteins serve various roles in the cell, including enzymes, transcription factors, and receptors, facilitating cellular functions and adaptations. The discussion highlights that the expression of specific genes through transcription and translation varies among different cell types, influencing their capabilities. For instance, lens cells focus light by producing crystallin proteins, while blood cells synthesize hemoglobin. It is emphasized that it is not the genes themselves that dictate cellular functions, but rather the transcription of specific genes influenced by external factors, such as surrounding connective tissue, that determines a cell's abilities and functions.