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Q30 - Bone Marrow Conversion - Red vs. Yellow Marrow With Age

Theoretical 1 Real exam question - full text reproduced under IBO's CC BY-NC-SA 4.0 license
Human Skeletal System

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).

Five skeletons of the lower limb at ages Birth, 7, 12-14, 18, and 25, showing red marrow (X) receding from the extremities and yellow marrow (Y) spreading toward the pelvis with age. 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.
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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)