Answer:
Temperatures gradient
Explanation:
There are distinct temperature gradient differences in the layers of atmosphere usually due to the main air molecule composition of the layers, the density of the molecules. The Troposphere the lowest layers is the densest and temperature decreases with increase in altitude. The stratosphere, on the other hand, has an increase in temperature with increase in altitude. Temperatures decrease with altitude in the mesosphere while the parameter increases with altitude in the thermosphere.
The nucleus is responsible for storing dna as well as the instuctions for protein synthesis
Selective permeable means it selects what goes out and comes into the cell. If the cell membrane wasnt selective then things could enter the cell and destroy it.
-Seth
