Final answer:
In a pedigree, if a trait skips generations and both males and females are affected, it suggests an autosomal recessive pattern of inheritance with the affected individuals having the 'aa' genotype. Unaffected parents who have an affected child must both be carriers. Autosomal recessive traits can affect both genders equally.
Step-by-step explanation:
When looking at a pedigree, if the trait in question skips generations and affects both males and females, it is typically indicative of an autosomal recessive pattern of inheritance. In such cases, individuals with the disorder are often represented by shaded symbols (squares for males and circles for females) and have the genotype aa where 'a' stands for the recessive allele. Those who are unaffected have at least one dominant allele and are represented in a different color in the pedigree.
Key characteristics of recessive inheritance include that an individual must have two copies of the recessive allele to exhibit the trait, and that it can skip generations if parents are carriers (heterozygous for the trait, with genotype Aa). For an affected child to be born from unaffected parents, both parents must be carriers of the recessive allele. The inheritance pattern is determined through the analysis of the pedigree, considering the representation of individuals across generations and their relationships to one another.
If we consider X-linked recessive diseases, males will have the disease or be genotypically normal, while females can be normal, carriers, or affected. However, autosomal recessive traits occur on chromosomes that do not determine sex, and thus, both males and females have an equal likelihood of inheriting the disease, unlike X-linked recessive diseases.