What is the expression pattern of an autosomal recessive trait?

The expression pattern of an autosomal recessive trait is characterized by the requirement of two copies of the recessive gene for the trait to be expressed. This means that an individual must inherit one recessive allele from each parent to exhibit the trait. If only one copy of the recessive allele is present, that individual will display the dominant trait associated with the other allele. This essential feature underscores the condition that for an autosomal recessive trait to be phenotypically visible, both alleles must be identical and recessive, hence leading to the conclusion that individuals expressing the trait are homozygous for that trait.