A cold air mass flowing away from its source region over a warmer surface will be warmed from below making the air more unstable in its lowest layers. A warm air mass flowing over a colder surface is cooled from below and becomes stable in its lowest layers.
Explanation:Introns are the non-coding portion of the DNA. They do not code for a gene that can be expressed hence the need for them to be removed from the coding genes(Exons). The exons are then joined together after the introns have been removed to create a sequence of amino acids.