Autosomal Recessive Trait.
Since neither II-3 nor II-4 is affected, this must be a recessive trait that has
skipped a generation; and
II-3 and II-4 must both be heterozygous.
Approximately 1/4 of their offspring should be affected, and II-3 and II-4 individuals can be represented by a shaded
dot
within their symbols.