Normal hemoglobin molecules may consist of each of the following EXCEPT which one?
A) 2 alpha and 2 beta chains
B) 2 alpha and 2 delta chains
C) 2 beta and 2 delta chains
D) 2 alpha and 2 gamma chains
E) 2 alpha and 2 epsilon chains

Question

Quizplus · Accepted Answer

Normal hemoglobin molecules consist of various combinations of globin chains, but they do not include a structure composed of 2 beta and 2 delta chains. The most common adult hemoglobin, HbA, consists of 2 alpha and 2 beta chains. HbA2, a minor adult hemoglobin, consists of 2 alpha and 2 delta chains. Fetal hemoglobin (HbF) consists of 2 alpha and 2 gamma chains. The epsilon chain is present in embryonic hemoglobin types, such as Hb Gower-1 (ζ2ε2) and Hb Gower-2 (α2ε2), but there is no normal hemoglobin variant composed of 2 beta and 2 delta chains.

Normal Hemoglobin Molecules May Consist of Each of the Following