ASCP Specialist in Hematology (SH) Practice Exam 2025 - Free Hematology Specialist Practice Questions and Study Guide

The gene loci for the alpha-globin chains are indeed adjacent to the locus for the zeta-globin chains. The human globin gene cluster is organized in a specific manner where the alpha-globin genes (HBA) are located on chromosome 16, and they sit alongside the zeta-globin genes (HBZ). This arrangement is a key part of the genetic framework that encodes for the different globin chains involved in hemoglobin production during various stages of development.

The zeta-globin chains are produced during embryonic development and later, alpha-globin chains take precedence in fetal and adult hemoglobin synthesis. Understanding the arrangement of these gene loci helps in comprehending the regulation of hemoglobin synthesis and can also play a role in diagnosing various blood disorders related to globin chain production.

The other choices represent different globin chains that do not share adjacent loci with the alpha-globin genes. Instead, they are located on different chromosomes or in differing positions within the genome, which emphasizes the significance of the proximity between the alpha and zeta loci in normal physiological conditions.