You cross a plant with red flowers with a plant with white flowers. both plants are pure-breeding. all the offspring have pink flowers. what allele relationship does this display?

The answer is incomplete dominance.

In incomplete dominance, heterozygous phenotype is intermediate between two homozygous phenotypes. For example, allele A is responsible for red color of a flower, allele B is responsible for white color of the flower. Red flower plants have AA genotype, and white flower plants have BB genotype. By crossing plants with red flowers and white flowers, due to incomplete variance, the offspring will be heterozygous plants (AB) with neither red nor white flowers, but pink flowers. Pink flowers have intermediate color between red and white flowers.

the food storage products of chrysophytes are oils or the polysaccharide laminarin.   formerly classified as plants, the chrysophytes contain the photosynthetic pigments chlorophyll a and c all but the yellow-green algae also contain the carotenoid pigment fucoxanthin.