Answer: Dominant: red, recessive: white.
Explanation:
Alleles are different forms or versions of a gene, and they can be described as either dominant or recessive.
Dominant traits are those that are seen in a heterozygous genotype. It means the organisms has two different alleles for a gene, one is dominant while the other one is recessive. A dominant allle dominates over the recessive alleles and it masks the effects of this recessive allele. This means, the offspring only needs to inherit one dominant allele to have a dominant trait.
In the example, a red-flowered plant is crossed with a white-flowered plant. And all plants on the next generation are red. If each plant from this offspring inherites one allele of each parent, they have one red allele and one white allele. Since they are all red, we can say red color is dominant and white color is recessive. Because red allele has a dominant phenotype.
