Question

the diagram shows an incomplete pedigree for the inheritance of an autosomal dominant trait (g). with autosomal dominant traits, only one copy of the gene is needed for the trait to be inherited and expressed by offspring. which option should go in spot ii - 1? options: black circle (female with trait), white box (male without trait), white circle (female without trait), black box (male with trait)

Explanation:

Since the trait is autosomal - dominant and the offspring (III - 1) has the trait, at least one of the parents (II - 1 and II - 2) must have the trait. II - 2 does not have the trait (white circle), so II - 1 must have the trait. Also, II - 1 is male (as per the pedigree structure and the key which shows squares for males). So II - 1 should be a male with the trait.

Answer:

black box (male with trait)