Final answer:
The assertion that CD34+ hematopoietic stem cells can differentiate into both myeloid and lymphoid stem cells is true, as they are responsible for the development of various blood cells crucial for the body's immune response and other functions.
Step-by-step explanation:
The statement that the CD34+ hematopoietic stem cell may differentiate into a myeloid or lymphoid stem cell is True. Hematopoietic stem cells, also known as hemocytoblasts, have the capability to generate all of the formed elements of blood. This process is a part of hematopoiesis, the development of blood cells. Myeloid stem cells are responsible for giving rise to red blood cells (erythrocytes), platelet-producing megakaryocytes, monocytes, and three types of granulocytes: neutrophils, eosinophils, and basophils. In contrast, lymphoid stem cells migrate from bone marrow to lymphatic tissues (like the lymph nodes, spleen, and thymus) to continue their production and differentiation, leading to lymphocytes, which include T cells, B cells, and natural killer (NK) cells important for immunity.