What is hyperplasia: (A) Decrease in cell size, (B) Increase in cell size, (C) Increase in cell number, (D) Decrease in cell number
Answer is C. Physiological adaptive responses include: 
◆ Hypertrophy - increase in cell size 
◆ Hyperplasia - increase in the number of cells 
◆ Atrophy - decrease in cell size and number
◆ Metaplasia - reversible replacement of one cell type by another differentiated cell type
 Hyperplasia is common in cells capable of replication namely labile cells / stable cells or stem cells