• Biological Growth (Growth in Living Organisms): In living organisms, growth is defined as an increase in mass and an increase in the number of individuals, which is exclusively intrinsic (occurs from within).

• Why is the odd one: Growth by cell division is only intrinsic (from inside) in living organisms. Extrinsic growth (growth from outside) is a feature of non-living objects (like mountains or crystals) due to the accumulation of material on their surface. Therefore, stating growth by cell division can be "extrinsic" is scientifically inaccurate for living organisms.