Ecosystems can be described by the types of

All types of ecosystems fall into one of two categories: terrestrial and aquatic.

Explanation:

Terrestrial ecosystems are land-based, while aquatic are water-based.

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.