How does the mechanism

of heredity work? Cellular DNA is the informa

tion source for making proteins in the cell. A secti

on of DNA that provides information for one protein is called the gene for that protein. How do proteins control the characteristics

that we are discussing here? Let us take t

he example of tallness as a characteristic. We know that plants have hormones that can trigger growth. Plant height can thus depend on the amount of a particular plant hormone. The amount of the plant hormone made w

ill depend on the efficiency of the process for making it. Consider now an enzyme that is important for this process. If this enzyme works efficiently, a lot of hormone will be made, and the plant will be tall. If the gene for th

at enzyme has an alteration that makes the enzyme less efficient, the amount of hormone will be less, and the plant will be short. Thus, genes control characteristics, or traits.