DNA is a genetic material found in chromosomes,which are present in the nucleus of the is a chemical  which carries genetic information required  by the cells  to divide and produce proteins.DNA is made up of genes.a set of genes are responsibe for the production of a specific protein . each protein is specific for its specific function.therefore , it is the DNA that decides the formation of a structural , enzymatic , hormonal and other components in an organism.genes are responsible for the physical appearance and body function of an organism.therefore , it is the DNA that gets transferred from the parents to the offsprings and makes them look similar.

hence we can conclude that due to efficiency of hormones some plants are tall and some r short.thus proteins are essential.