Question

When exposed to bright sunlight, some people involuntarily sneeze. This reaction is known as a 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).

Answer 1

dominant-recessive

Step-by-step explanation:

Photic sneeze reflex is an autosomal dominant or dominant-recessive disorder that means that person having only a single dominant allele of the gene of trait will suffer from the disorder irrespective of the sex.

As mentioned in the question, the Photic sneeze reflex disorder is a condition in which a person, when exposed to bright sunlight,involuntarily sneeze.

Since the disorder is autosomal dominant, it means that A man and a woman who sneeze when exposed to bright sunlight can both be heterozygous for the photic response trait. Therefore, if one of the if one parents is affected, there are 50% chances that the child will inherit syndrome and be effected.

If you want to better understand the pattern of autosomal dominant or dominant-recessive disorders, please see attached image.

Hope it helps!