In *Mirabilis jalapa*, commonly known as the four o'clock flower, the phenotype of a heterozygous plant displays **incomplete dominance** for flower color. This means that the heterozygous genotype (Rr) results in a blend of the two parent phenotypes.- **RR** (homozygous dominant): Red flowers- **rr** (homozygous recessive): White flowers- **Rr** (heterozygous): Pink flowersSo, the phenotype of a heterozygous four o'clock flower is **pink**.
Answer:The Phenotype of Heterozygous is Pink Flowers.