Which term describes an increase in size of a structure due to an increase in the number of cells?

The correct term that describes an increase in size of a structure due to an increase in the number of cells is hyperplasia. Hyperplasia occurs when there is an increase in cell production, ultimately leading to the enlargement of a tissue or organ. This can happen as a normal physiological response, such as during puberty or wound healing, or it can be pathological, as seen in certain conditions like benign prostatic hyperplasia.

In contrast, hypoplasia refers to underdevelopment or incomplete development of a tissue or organ, leading to a reduced number of cells. Hypertrophy involves an increase in the size of cells rather than an increase in cell number, which also contributes to the enlargement of the organ or tissue but through different mechanisms. Aplasia is a condition where there is an absence of tissue or organ development, resulting in a significant lack of cell presence. Therefore, hyperplasia accurately captures the phenomenon of tissue growth due to an increase in the number of cells, distinguishing it from the other terms.