Final answer:
The correct pathway for monocyte formation in leukopoiesis is from hematopoietic stem cells (HSC), myeloid cell line, to monoblast, promonocyte, and then monocyte. Monocytes are agranular leukocytes derived from myeloid stem cells, not lymphoid cells.
Step-by-step explanation:
Leukopoiesis is the process through which different types of white blood cells (leukocytes) are formed. Specifically, monocytes are derived from myeloid stem cells. The correct pathway for the formation of a monocyte through the process of leukopoiesis is: hematopoietic stem cells (HSC), myeloid cell line, monoblast, promonocyte, and ultimately the monocyte. The lymphoid cell line is responsible for the production of lymphocytes, which include B cells, T cells, and natural killer (NK) cells. Consequently, the correct sequence is 'HSC, myeloid cell line, monoblast, promonocyte, monocyte.' Monocytes are agranular leukocytes that circulate in the bloodstream and can differentiate into macrophages or dendritic cells, playing essential roles in the immune system.