When exposed to bright sunlight, some people involuntarily sneeze. this reaction is known as photic response. it is controlled by a single gene with two alleles, h and h. a man and a woman who sneeze when exposed to bright sunlight are both heterozygous for the photic response trait. identify the most likely inheritance pattern for this trait (dominant-recessive, codominant, sex-linked, or polygenic) !

Ans.

Photic response or sneezing due to exposure of bright sunlight is a genetically inherited trait. A given, both man and woman are showing photic response and are heterozygous (Hh) for the trait.

It indicates that 'the inheritance pattern for photic response is autosomal dominance,' means the mutated allele (H) for the trait is dominant over normal or recessive gene (h),  and presence of only copy of it can shows its effect.

Thus, the correct answer is 'dominant-recessive.'