What do genes control?

Genes are segments of DNA that carry the instructions for the synthesis of proteins, which play crucial roles in the development and functioning of an organism. Each gene typically corresponds to a specific trait, such as eye color, blood type, or susceptibility to certain diseases. This specificity is due to the unique sequences of nucleotides in the gene that dictate the sequence of amino acids in a protein, eventually affecting a particular characteristic.

While DNA replication, RNA function, and cell division are vital cellular processes, they are broader biological activities not directly controlled by a single gene. DNA replication involves numerous genes and proteins working together to ensure accurate copying of genetic material. RNA function involves various types of RNA, including messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA), orchestrated by multiple genes and regulatory mechanisms. Likewise, cell division is controlled by a network of genes and proteins that orchestrate the complex process of mitosis or meiosis, involving checkpoints and regulation that go beyond the influence of a single gene.

In summary, the defining role of genes is to determine specific traits by encoding the necessary information to produce proteins that influence those traits, making this the most accurate answer among the options provided.