Question

Incomplete dominance is shown by

• A. Primrose
• B. Mirabilis
• C. Helianthus
• D. China rose

Answer 1

Answer: (B)

When $F_1$ hybrids exhibited a mixture of characters of two parents, the case is considered as that of incomplete or blending inheritance. It simply means that two genes o allelomorphic pair are not related as dominant on recessive, but each of them express itself partially. For example, in 4 Oclock plant (Mirabilis jalapa), when plants with red flower (homozygous, RR) are crossed with plants having white flower (homozygous, rr), the heterozygous $F_1$ hybrid (Rr) bear pink flower. When these pink flowered plants are self-pollinated they develop red (RR), pink (Rr) and white (rr) flowers in the ratio 1 : 2 : 1 respectively.