CBSE Class 10 Science 2022 · Paper 31/4/1 · Question 3(a)

A gene is a section of DNA that provides the information for making a protein, and many proteins are enzymes. Plants have hormones that trigger growth, so the height of a plant depends on the amount of a particular plant hormone. The amount of hormone made depends on the efficiency of the process that makes it, which is carried out by an enzyme, and the enzyme is made from the information in a gene. If the gene for this enzyme is normal, the enzyme works efficiently, a lot of hormone is made and the plant is tall. If the gene has an alteration that makes the enzyme less efficient, less hormone is made and the plant is short (dwarf). So a change in the gene changes the enzyme, the amount of hormone and the height: genes control the characteristics or traits of an organism.