Final answer:
The statement is true because genomic imprinting can lead to different phenotypes in two heterozygous individuals due to the parent-of-origin-specific expression of imprinted genes, affecting the observable traits despite the same underlying genotype.
Step-by-step explanation:
The statement is true: due to genomic imprinting, two individuals who are both heterozygous for a gene that is imprinted can have different phenotypes concerning the trait determined by that gene.
Genomic imprinting is a process by which certain genes are expressed in a parent-of-origin-specific manner. This is an exception to the typical Mendelian inheritance. In the case of an imprinted gene, the phenotype is not solely determined by the presence of dominant or recessive alleles but also by the parental origin of those alleles. Consequently, even individuals with the same genotype, where one gene is imprinted, may show different phenotypes depending on whether the imprinted allele was inherited from the mother or the father.
Phenotypes represent the observable traits of an organism, while genotypes represent the underlying genetic makeup, including both expressed and non-expressed alleles. Genomic imprinting can cause two heterozygous individuals to express different phenotypes even though they have the same genotype due to differential expression of the imprinted gene.