If the cross of a red-flowered plant with a white-flowered plant produces a pink-flowered plant, it is an example of

Step 1: Analyze the question A red-flowered plant crossed with a white-flowered plant gives pink offspring. The offspring's phenotype is an intermediate blend of the two parents' phenotypes.

Step 2: Explain the concept

• Complete dominance: one allele completely masks the other (e.g., tall × short gives all tall).
• Incomplete dominance: neither allele is fully dominant, so the heterozygote shows a blend or intermediate phenotype.
• Codominance: both alleles are expressed fully and separately in the heterozygote (e.g., AB blood group, or a red-and-white spotted flower).
• Mutation: a sudden change in the genetic material.
• Linkage: genes on the same chromosome tend to be inherited together.

Step 3: Work through it Let R = red allele and W = white allele.

• Parents: RR (red) × WW (white)
• F1 offspring: all RW, which are pink

The pink colour is a mix of red and white. Neither allele masks the other, and the colours do not appear side by side. That is a blending effect, which is incomplete dominance.

If this were codominance, the flowers would show patches of red and white together, not a uniform pink.

If the F1 pink plants are crossed (RW × RW), the F2 ratio is 1 red : 2 pink : 1 white. This 1:2:1 ratio is the classic sign of incomplete dominance. It differs from the 3:1 ratio of complete dominance.

Step 4: Answer The correct option is B. incomplete dominance.

Tip: Remember "blend = incomplete, both = co." Incomplete dominance gives a mixture (red + white = pink). Codominance shows both traits clearly (red patches and white patches). Classic examples to know are the four o'clock plant (Mirabilis jalapa) and snapdragons for incomplete dominance.