Pernicious anemia may result from __________.

rupture of red blood cells caused by parasites

the lack of vitamin B₁₂ in the diet or a deficiency of the intrinsic factor needed to absorb vitamin B₁₂

excessive bleeding

the absence or depressed synthesis of globin chains

abnormal production of hemoglobin caused by genetic defect

Master Red Blood Cell Life Cycle and Disorders with a bite sized video explanation from Alila Medical Media