Q30 — Bone Marrow Conversion — Red vs. Yellow Marrow With Age
The figure represents the distribution of bone marrow types X and Y in the lower limbs of humans (Homo sapiens) at different ages (in years).
Distribution of marrow type X (red/haematopoietic) and type Y (yellow/fatty) in the lower limb at birth, age 7, 12–14, 18, and 25. Marrow type X recedes from the extremities toward the pelvis as age increases; the pelvis still retains type X marrow even at age 25.
Using the information and figure, determine whether the following statements are true or false:
A. The reduction in marrow type X is initiated in puberty.
B. A healthy adult does not have a significant amount of marrow type X in his pelvis.
C. Conversion of marrow type X to Y is reversible.
D. A patient with leukemia can be assigned for a transplant of bone marrow type Y.
Question reproduced from IBO 2022, Theoretical Paper 1, licensed under CC BY-NC-SA 4.0 — attributed to the International Biology Olympiad. Open the full exam PDF · Community solutions (unofficial)