Haemopoiesis Practice Questions
20 free Haemopoiesis practice questions for the Physiology. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
Which of the following is the pluripotential stem cell from which all blood cells are derived?
- A Hemocytoblast
- B Myeloblast
- C Proerythroblast
- D Megakaryocyte
Correct answer: Hemocytoblast
The hemocytoblast, also known as the pluripotent hematopoietic stem cell (PHSC), is the common ancestor of all formed elements of the blood. Residing in the bone marrow, it differentiates into myeloid or lymphoid progenitor cells, which in turn give rise to the myeloblast, proerythroblast, megakaryocyte, and other lineage-committed precursors.
During fetal development, which organ is the primary site of hematopoiesis during the middle trimester (3–6 months)?
- A Fetal liver
- B Yolk sac
- C Bone marrow
- D Thymus
Correct answer: Fetal liver
Hematopoiesis begins in the yolk sac during the first few weeks of gestation. By the second trimester, the fetal liver becomes the dominant site of blood cell production, before the bone marrow takes over as the primary site in the final trimester.
Which specific lineage produces Natural Killer (NK) cells?
- A Common Lymphoid Progenitor
- B Common Myeloid Progenitor
- C Granulocyte-monocyte Progenitor
- D Megakaryocyte-erythroid Progenitor
Correct answer: Common Lymphoid Progenitor
NK cells, along with T-lymphocytes and B-lymphocytes, are derived from the lymphoid lineage. The myeloid lineage is responsible for erythrocytes, platelets, and most white blood cells like neutrophils.
Which of the following describes the correct order of erythropoiesis stages?
- A Proerythroblast -> Basophilic erythroblast -> Polychromatophilic erythroblast -> Reticulocyte
- B Basophilic erythroblast -> Proerythroblast -> Reticulocyte -> Polychromatophilic erythroblast
- C Polychromatophilic erythroblast -> Reticulocyte -> Basophilic erythroblast -> Proerythroblast
- D Reticulocyte -> Polychromatophilic erythroblast -> Proerythroblast -> Basophilic erythroblast
Correct answer: Proerythroblast -> Basophilic erythroblast -> Polychromatophilic erythroblast -> Reticulocyte
Erythropoiesis proceeds in order from the proerythroblast to the basophilic erythroblast to the polychromatophilic erythroblast, and finally to the reticulocyte stage, before full maturation into the erythrocyte. This progression reflects increasing hemoglobin synthesis and progressive condensation of the nucleus.
At which stage of erythropoiesis is the nucleus typically extruded from the cell?
- A Basophilic erythroblast
- B Polychromatophilic erythroblast
- C Reticulocyte
- D Orthochromatic erythroblast
Correct answer: Orthochromatic erythroblast
The orthochromatic erythroblast, also called the late normoblast, is the stage at which the nucleus becomes non-functional and is extruded from the cell, leaving behind a reticulocyte that later matures into a mature erythrocyte.
Which vitamin is essential for DNA synthesis during hematopoiesis, and its deficiency leads to megaloblastic anemia?
- A Vitamin C
- B Vitamin K
- C Vitamin E
- D Vitamin B12
Correct answer: Vitamin B12
Vitamin B12 and Folic acid are cofactors required for the synthesis of thymidine triphosphate, a building block of DNA. Without them, cell division is impaired, resulting in abnormally large and fragile red blood cells.
Thrombopoietin, the hormone that stimulates platelet production, is primarily produced in the:
- A Liver
- B Kidneys
- C Spleen
- D Red bone marrow
Correct answer: Liver
While erythropoietin is mainly produced in the kidneys, thrombopoietin is primarily synthesized and released by the liver. It stimulates the production and differentiation of megakaryocytes.
Which of the following cells is a direct precursor to the thrombocyte (platelet)?
- A Monoblast
- B Lymphoblast
- C Myelocyte
- D Megakaryocyte
Correct answer: Megakaryocyte
Megakaryocytes are giant cells in the bone marrow that undergo cytoplasmic fragmentation. These fragments are released into the blood as platelets.
What happens to the iron released from degraded hemoglobin during the recycling phase of hematopoiesis?
- A It is immediately filtered out and excreted by the kidneys
- B It is stored in the liver as ferritin or hemosiderin
- C It is converted into bilirubin for excretion in bile
- D It is converted into bile salts for fat digestion
Correct answer: It is stored in the liver as ferritin or hemosiderin
Iron is highly conserved by the body. Once released from old RBCs, it binds to transferrin for transport and is stored in the liver as ferritin or reused in the bone marrow for new hemoglobin synthesis.
Colony-stimulating factors (CSFs) primarily regulate the production of which blood components?
- A Erythrocytes
- B Leukocytes
- C Platelets
- D Plasma proteins
Correct answer: Leukocytes
CSFs are glycoproteins that bind to receptor proteins on the surfaces of hemopoietic stem cells, stimulating the proliferation and differentiation of various white blood cell lines.
Which of the following is the first recognizable cell of the granulocytic series?
- A Myeloblast
- B Metamyelocyte
- C Band cell
- D Promyelocyte
Correct answer: Myeloblast
The myeloblast is the earliest identifiable precursor in granulopoiesis. It differentiates into the promyelocyte, which then develops into specific types of myelocytes (neutrophilic, eosinophilic, or basophilic).
In a healthy adult, which of these bones would likely contain active red bone marrow?
- A Distal tibia
- B Shaft of the radius
- C The sternum
- D Phalanges
Correct answer: The sternum
In adults, red marrow is restricted to the axial skeleton (skull, vertebrae, ribs, sternum) and the girdles. The shafts of long bones in the limbs are typically filled with inactive yellow marrow.
The hormone erythropoietin is released in response to which physiological trigger?
- A High blood pressure
- B Low tissue oxygen levels (hypoxia)
- C A significant increase in blood glucose levels
- D A noticeable decrease in blood plasma pH
Correct answer: Low tissue oxygen levels (hypoxia)
Sensors in the kidney detect a decrease in oxygen delivery. In response, they increase the secretion of erythropoietin to boost the oxygen-carrying capacity of the blood by increasing RBC count.
What is the primary characteristic of a reticulocyte that distinguishes it from a mature erythrocyte?
- A Presence of a nucleus
- B Presence of numerous mitochondria and other organelles
- C Presence of a ribosomal network (RNA)
- D A complete inability to transport oxygen molecules
Correct answer: Presence of a ribosomal network (RNA)
Reticulocytes are immature red cells that have recently ejected their nucleus but still contain residual organelles and ribosomal RNA. This network appears as a 'reticulum' when stained with supra-vital dyes.
Which cytokine is specifically known for its role in eosinophil production and activation?
- A Interleukin-1
- B Interleukin-5
- C Interleukin-10
- D Tumor Necrosis Factor
Correct answer: Interleukin-5
Interleukin-5 (IL-5) is a key growth factor for the eosinophil lineage. It is vital for the maturation of eosinophils in the marrow and their recruitment during allergic reactions or parasitic infections.
The process where a single stem cell divides to produce one daughter stem cell and one specialized cell is called:
- A Apoptosis
- B Symmetric division
- C Asymmetric division
- D Agglutination
Correct answer: Asymmetric division
Asymmetric division is essential for hematopoiesis because it ensures the stem cell pool is maintained (self-renewal) while simultaneously providing cells that can differentiate into mature blood types.
Intrinsic factor, secreted by the stomach, is necessary for the absorption of which hematopoietic nutrient?
- A Iron
- B Folic acid
- C Vitamin B12
- D Pyridoxine (B6)
Correct answer: Vitamin B12
Intrinsic factor binds to Vitamin B12 in the small intestine, allowing it to be absorbed in the ileum. A lack of intrinsic factor leads to Pernicious Anemia.
Which cell type in the bone marrow is responsible for creating the 'niche' or microenvironment for stem cells?
- A Osteoclasts
- B Stromal cells
- C Erythroblasts
- D Adipocytes only
Correct answer: Stromal cells
Hematopoietic induction microenvironments (HIM) are created by stromal cells, including fibroblasts, endothelial cells, and macrophages. They provide the physical support and chemical signals (cytokines) needed for stem cell survival.
Monocytopoiesis results in the formation of monocytes, which eventually differentiate into:
- A Plasma cells
- B Macrophages
- C Mast cells
- D Platelets
Correct answer: Macrophages
Monocytes are the circulating precursors of the mononuclear phagocyte system. After entering tissues, they enlarge and become macrophages, such as Kupffer cells in the liver or microglia in the brain.
Which of the following is a symptom of 'extramedullary hematopoiesis'?
- A Enlargement of the liver and spleen
- B Shrinking of the lymph nodes
- C Hardening of the long bones
- D Excessive production of yellow marrow
Correct answer: Enlargement of the liver and spleen
When bone marrow is damaged or unable to meet the body's demands, the liver and spleen can revert to their fetal function of producing blood cells. This results in hepatosplenomegaly.