Final answer:
Genes that come from both parents and carry information for the same trait but consist of different alleles are heterozygous. If both alleles are dominant or both are recessive, the genes are homozygous. The observed physical traits of the organism, its phenotype, are a result of the interaction between these alleles.
Step-by-step explanation:
The characteristic of genes that come from different sources (mom and dad) but carry genes for the same traits are known as alleles. When an individual has two different alleles for the same trait, one inherited from each parent, they are referred to as heterozygous genes. For instance, if the trait is for cleft chin and one parent donates a dominant cleft chin allele (B) and the other parent donates a recessive smooth chin allele (b), the offspring's genotype would be Bb, which is heterozygous. The dominant allele in this case would determine the phenotype, resulting in a cleft chin.