Mark the correct statement from the following

The correct option is "growth in living organisms is from inside".

Let us analyze each statement to understand why this is the correct choice:

1. "plants grow but only up to a certain age": This statement is incorrect. Plants exhibit indeterminate growth, meaning they continue to grow and divide throughout their entire life span due to the presence of active meristematic tissues at their root and shoot tips.
2. "only living organisms grow": This statement is also incorrect. Non-living things can also exhibit a form of growth by accumulation of material on their surface. For example, mountains, boulders, and sand dunes grow in size over time. However, this growth is due to external deposition.
3. "growth in living organisms is from inside": This statement is correct. Growth in living organisms is an intrinsic process (intussusception). It occurs from within the body due to cell division and cell enlargement, resulting in an increase in cell number and cell mass. Unlike non-living objects where material accumulates externally, living organisms build up their body mass from the inside.
4. "All of the above": Since the first two statements are incorrect, this option is also incorrect.

Therefore, the only scientifically accurate statement is that growth in living organisms occurs from the inside.