Cellular DNA is the information sorce for making proteins in cell. Genes are
functional segments of DNA and each gene is associated with synthesis of a single protein.
These proteins could act as hormones or some may be enzymes. Depending on the amounts produced, a particular characteristic is controlled. For example - plant height depends on the amount of a f a particular plant hormone.
The amount of the plant hormone made will depend on the
efficiency of the process for making it.