An embryo exhibits abnormal development in the most posterior part of its body.The responsible Hox gene is located
A) close to the 3′ end of the Hox gene complex.
B) at the 5′ end of the Hox gene complex.
C) in the middle of the Hox gene complex.
D) at the 3′ end of the Hox gene complex.
E) in another gene complex.

Question

Quizplus · Accepted Answer

Hox genes are arranged in a sequence that reflects their expression along the anterior-posterior axis of the body, with genes at the 3′ end expressed in anterior regions and those at the 5′ end expressed in posterior regions. Therefore, abnormalities in the most posterior part of the body would be associated with genes located at the 5′ end of the Hox gene complex.

An Embryo Exhibits Abnormal Development in the Most Posterior Part