Question

What is the molecular explanation for Mendel’s tall and dwarf planets?

Answer 1

A single gene with two alleles controls the height of the pea plant. 

The difference in height of the plant is due to:

1. The pea plant cells have the ability to convert a precursor molecule of gibberellins into an active form (GA₁).
2. The dominant allele of the gene (Le), which codes for a protein, a functional enzyme, which helps in the gibberellin synthesis pathway and catalyzes the production of gibberellins (GA₁). When the allele is dominant even if it is double (Le Le) or single (Le le) it produces gibberellins resulting in tall plants. The dwarf pea plants, which have two recessive alleles (le le) cannot code for functional protein resulting in dwarf plants.