The synthesis of flower pigments is known to be dependent on enzymatically controlled biosynthetic pathways. For the crosses shown here, postulate the role of mutant genes and their products in producing the observed phenotypes: P₁: white×pink F₁: all purple F₂: 9/16 purple: 3/16 pink: 4/16 white

Key Concepts

Biosynthetic Pathways

Biosynthetic pathways are series of enzymatic reactions that lead to the production of complex molecules from simpler ones. In the context of flower pigments, these pathways involve specific enzymes that catalyze the conversion of precursor compounds into pigments, influencing the color of the flowers. Understanding these pathways is crucial for analyzing how mutations in genes can affect pigment production and, consequently, flower color.

Genetic Inheritance Patterns

Genetic inheritance patterns describe how traits are passed from parents to offspring, often illustrated through Mendelian ratios. In this case, the observed phenotypic ratios in the F₂ generation (9:3:4) suggest a dihybrid cross involving two genes, where one gene may be epistatic to another. Recognizing these patterns helps in predicting the outcomes of genetic crosses and understanding the role of dominant and recessive alleles.

Mutant Genes and Phenotypes

Mutant genes are altered versions of normal genes that can lead to changes in phenotype, which is the observable expression of traits. In the context of the flower color experiment, mutations in genes responsible for pigment synthesis can result in different colors, such as white, pink, or purple. Analyzing how these mutations affect the enzymatic pathways involved in pigment production is essential for explaining the observed phenotypic ratios.