homozygous and heterozygous. homozygous has same allele for a particular trait, heterozygous has different.

homozygous heterozygous chromosome allele gene genetics trait dominant recessive pair dna genotype phenotype variation combination science medicine diagram research biology maternal paternal inheritance reproduction genome code replication mitosis diploid parents offspring human gamete haploid chromatids centromere telomere homologous disorder hybrid chromatin division identical homozygote heterozygote deoxyribonucleic acid disease vector locus