MAOI's work better with patients whose depression becomes more acute as the day progresses. An enzyme named monoamine oxidase is intricate in eliminating the serotonin, neurotransmitters norepinephrine and dopamine to the brain. MAOIs avoid this from happening which makes more of these brain chemicals obtainable to effect alterations in together cells and circuits that have been obstructed by depression.
When a cell is differentiated that means it is no longer a ''blank canvas'', a pluripotent cell (like the stem cells).
Let's take a muscle cell as an example.
Before it is differentiated, it is just like all of the other stem cells.
But after the expression of genes specific for muscle cell and the resulting changes in structure and physiology of the cell, this cell becomes a muscle cell.
Afterward, the differentiated muscle cell communicates integrates with other muscle cells into the muscle tissue. The muscle tissue eventually forms organs like skeletal muscles, the heart and similar.
I believe vestigial structures are evidence of evolution because organisms inherit anatomy from their ancestors.
Hope that helps.
Radiative zone is the region of sun where energy moves as waves that transfer from atom to atom.