So a disease is said to be recessive if only the homozygous recessive individual, the homozygous recessive genotype actually creates that particular phenotype for that particular disease. So a disease is autosomal recessive, if only the homozygous recessive individual for that particular trait expresses that phenotype for that disease. And the genetic abnormality exists on the autosome and not on the sex chromosome. So to see what we mean, let's take a look at the following three diagrams. So we basically have an autosome on which both of these genes are fully functional and they're represented by uppercase DS. So this is homozygous dominant, and a homozygous dominant individual will have a normal phenotype, and they will not be a carrier for that particular disease.