Final answer:
Lymphocytes originate from lymphoid stem cells, which are a type of hematopoietic stem cell, while monocytes come from the myeloblast lineage that arises from myeloid stem cells.
Step-by-step explanation:
Lymphocytes and monocytes are both types of white blood cells that arise from hematopoietic stem cells (HSCs).
Lymphocytes are derived from lymphoid stem cells and are a critical part of the immune system, including T cells, B cells, and natural killer (NK) cells. On the other hand, monocytes, which mature into macrophages, are part of the myeloblast lineage that originates from myeloid stem cells. These stem cells are diverse and give rise to a range of formed elements in the blood, extending far beyond just lymphocytes and monocytes.