Answer: Directional selection occurs when individuals with traits on one side of the mean in their population survive better or reproduce more than those on the other. ... Directional selection does the “heavy lifting” of evolution by tending to move the trait mean toward the optimum for the environment.
The sodium hydroxide solution and vegetable oil underwent a chemical change.
<h3><u>Explanation:</u></h3>
The reaction between a base and a fat or fatty acid is called as saponification reaction. Here the base dissociates into the cation and hydroxyl ion. The hydrogen from the fatty acid of the oil reacts with the hydroxyl ion to form water which is basically the neutralization reaction. This cation now reacts with the rest of the fatty acid to form a bipolar molecule which is the soap. During the reaction, the solution becomes cloudy but with time, it again goes back to solution. The cloudyness appears because oil isn't soluble in water based solutions and the base is actually made solution in water.
Here the sodium hydroxide reacts with oil to form water and the soap molecule which is a chemical change.
An example of decomposers in the desert could be worms, beetles, or bacteria. Decomposers can't always stay alive because of the drought. Good luck!!
Hotspots can appear in oceans around the world or anywhere there is a hotspot they don't need to be near plate boundaries like most volcanos