Question

“Proteins control the expression of various characters.” Explain this statement by taking the example of “tallness” as a characteristic in plants.

Answer 1

Proteins play an important part in determining traits by acting as enzymes, hormones, or structural components. The genes in DNA provide instructions for synthesizing these specific proteins, which in turn influence the expression of traits.

For instance, a dominant gene controls tallness (T) in pea plants. This gene is responsible for producing a protein (enzyme) that regulates the synthesis of gibberellins, a plant hormone that promotes stem elongation. If the dominant allele (T) is present, an efficient protein is made, leading to ample gibberellin and a tall plant. However, if the recessive allele (t) is present, the protein produced is less efficient, resulting in low gibberellin production and a short plant.