Question

Dominant allele determine the genotype of the organism?

Answer 1

No, dominant allele doesn't determine the genotype of the organism as there are some recessive allele too but they are unable to express.
Hope it helps u dear

Answer 2

See in first flial generation in case of complete domince its the dominant allele that determines genotype of an organism. But as Mendel' first laq or law of dominance is not universally applicable dominant alleles fail to express themselves when it is not the case of complete dominance. Example in cases of incomplete dominance like flower colour of mirablis jalapa in first flial generation is pink where progeny are heterozygous and dominant allele R is not able to express itself over recessive white