mr. r has beta-thalassemia minor; he is heterozygous for the beta-thalassemia gene, so he only makes half as many beta chains as normal. the red blood cells containing abnormal hemoglobin are destroyed more rapidly, so mr. r suffers from mild anemia (low hematocrit). what are the beta chains, and why are they important in the hemoglobin molecule? choose the best answer. mr. r has beta-thalassemia minor; he is heterozygous for the beta-thalassemia gene, so he only makes half as many beta chains as normal. the red blood cells containing abnormal hemoglobin are destroyed more rapidly, so mr. r suffers from mild anemia (low hematocrit). what are the beta chains, and why are they important in the hemoglobin molecule? choose the best answer. beta chains are the part of the erythrocyte that holds the hemoglobin in position so it can properly receive oxygen. beta chains are the part of the hemoglobin that carries oxygen. all of the protein in hemoglobin is beta chains; therefore, hemoglobin could not exist without them. beta chains are two of the four protein chains that hold heme groups in position and modulate their oxygen-binding properties.