Answer:
Structural adaptation
Explanation:
When any physical body part of an organism helps it in surviving, then this mechanism of survival is called a structural adaptation. For example short tail of penguins helps them in balancing on their heels and tails due to which they are able to reduce heat released from their feet. Thus, any physical parts of an organism that helps them in coping with the surrounding physical environment /predators are refereed to as a mode of structural adaptation.
The main determining factor in defining boundaries between layers of earth's atmosphere would be temperature changes in these layers. Temperature is one essential property that varies in the atmosphere. Based from this variation, the atmosphere is divided into four major layers and further to three smaller layers - troposphere, tropopause, the stratosphere, stratopause, the mesosphere, mesopause, and the thermosphere.The troposphere is the layer that is nearest to the surface of the Earth. It is the part where humans, plants and animals survive. Also, it is the warmest layer of the atmosphere. And as we go higher the atmosphere, the temperature would drop making it much cooler.