Answer :

Entisols are young soils that are usually found in areas with recent geological activity or in locations where soil formation processes have been limited. These soils have minimal development of soil horizons or layers. On the other hand, old soils are more developed with distinct horizons due to prolonged soil-forming processes over time.

1. True: Entisols can be either young or old, but they are generally characterized as undeveloped because they lack well-defined horizons.
2. False: Entisols are typically young soils with limited development, making them distinct from older soils that have undergone more advanced soil formation processes.

In summary, the statement that Entisols are either young or old soils which are undeveloped is mostly true as they are often associated with young or minimally developed soil profiles.