Answer:
The statement is true
Explanation:
Hematopoietic stem cells give rise to myeloid progenitor and lymphoid progenitor and these two progenitors give rise to many immune cells. Dendritic cells are produced by both the progenitors and macrophages are produced by myeloid progenitor.
Both macrophages and dendritic cells are phagocytes. In phagocytosis, the foreing particles are injected by these phagocytes and they are destryoyed by the action of digestive enzymes present in these phagocytic cells.
Macrophages are present in tissue and if they are present in blood they are called monocytes. Therefore the statement is true.
Answer:
Which of the following properties describes a direct current system but not an alternating current system?
The current always flows it the same direction.
Explanation:
When current flows in the same direction, it is described to have flow in a direct manner rather than an alternate system
Answer:
America and Canada I think
Explanation:
