Name the phenomenon that results when a red flower plant is crossed with a white flowered plant and the offspring have pink flowers.

Codominance.

Explanation:

You have two parents whit heterozygous characteristics, and both are dominant the offspring have two dominant alleles, and the phenotype will be a combination of both.

In this case, you have a dominant white WW and a dominant redRR, together they made the codominant pink WR.

In humans, you can found codominance in blood type AB. A and B are both dominant over 0, and when combine they both shown.