MCAT® ExamBiological and Biochemical Foundations of Living SystemsMedium
A patient is experiencing chronic fatigue, weight loss, and frequent infections. Blood tests reveal a significant decrease in the number of all types of blood cells, including red blood cells, white blood cells, and platelets. The physician suspects a problem with the production of these cells. Which biological process is most likely impaired?
- AGluconeogenesis
- BHematopoiesis
- CGlycolysis
- DApoptosis
Show answer & explanationAnswer & explanation
Correct answer: B. Hematopoiesis
Hematopoiesis is the process by which all blood cells (red blood cells, white blood cells, and platelets) are formed from hematopoietic stem cells in the bone marrow. A significant decrease in all blood cell types points directly to an impairment in this process.
Why the other options are wrong
- A. Gluconeogenesis is the synthesis of glucose from non-carbohydrate precursors.
- C. Glycolysis is the metabolic pathway that converts glucose into pyruvate, primarily for energy production.
- D. Apoptosis is programmed cell death, which, while involved in cell turnover, wouldn't typically cause a global decrease in all blood cell types in this manner.
Hematopoiesis
The process of blood cell formation, including red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes), from hematopoietic stem cells in the bone marrow.
- Occurs primarily in red bone marrow in adults.
- Involves hematopoietic stem cells (HSCs).
- Produces all types of blood cells.
- Regulated by growth factors and cytokines.
Memory trick: Hemato-poiesis: Making blood, like a factory.