An organism can be homozygous dominant, if it carries two copies of the same dominant allele, or homozygous recessive, if it carries two copies of the same recessive allele. Heterozygous means that an organism has two different alleles of a gene.
AKA: homozygous can be 2 upper or 2 lower case letters and Heterozygous is 1 upercase and 1 lower case letter
