Pedigree logic

Parallel family, not your case: Generation I, an affected father and an unaffected mother. Generation II, their affected son, their affected daughter and their unaffected daughter. Generation III, the affected son and his affected wife have an affected son and an unaffected daughter.

I drew the family using standard symbols: squares for males, circles for females, filled-in shapes for affected individuals, and a horizontal line for each mating.

Mode of inheritance: In this parallel family the trait is autosomal dominant.

Evidence from the pattern: Every affected child has at least one affected parent, and the trait shows up in all three generations, which fits a dominant allele. Generation III rules out recessive, because two affected parents have an unaffected daughter. If the trait were recessive, both parents would be aa, and every child of theirs would be aa and affected. In Generation I an affected father and an unaffected mother have an affected son. A father gives his son a Y chromosome, not an X, so the son's allele came through an autosome. The same father has an unaffected daughter, and an affected father gives his X to every daughter, so the trait is not X-linked dominant either. That makes it autosomal dominant.

Carriers I circled: None. With a dominant trait, anyone who carries the allele shows it, so there is no unaffected carrier to circle. (A real family can break this rule when an allele does not always show, and a pedigree alone cannot tell you that.) Instead I labeled genotypes. The Generation I father must be Aa, not AA, because his unaffected daughter is aa and got one a from him. The same logic makes the affected son and his affected wife both Aa, because their unaffected daughter is aa.

Your family can give a different answer. Test each pattern against every parent and child in your own pedigree before you call it.