Question

Aaron is a healthy, 65-year-old man. Compared with his 24-year-old son Harry, Aaron has much less brain volume. Which of the following is most likely the reason for this difference?

A) Harry has a lower number of synapses than Aaron has.
B) Aaron is experiencing shrinkage of neurons.
C) Aaron has a thicker corpus callosum than Harry has.
D) Harry has reduced tree-like branching in the dendrites of his brain.

Answer 1

Aaron's reduction in brain volume compared to his son Harry is most probably due to the natural shrinkage of neurons, which is a part of the aging process known as neurodegeneration.

Step-by-step explanation:

The difference in brain volume between Aaron, the 65-year-old man, and his 24-year-old son Harry, is most likely attributed to brain shrinkage associated with aging. During the aging process, there is a natural decline in the number and function of neurons and the connections between them. This phenomenon is known as neurodegeneration and leads to a decrease in brain volume over time. This shrinking is not due to a reduction of synapses in Aaron compared to Harry, nor is it likely that Aaron's corpus callosum is thicker. Instead, it is more plausible that Aaron is experiencing shrinkage of neurons. Furthermore, it is unlikely that Harry would have reduced branching in the dendrites of his brain at his age, as dendritic growth and complexity typically peak during young adulthood.