I'm not sure if it's the "best" example but.
If your blood tempature is low, the hypothalamus will issues reflex commands that make your body shiver. If you are hot, you will sweat is the opposite of this.
Another example is, if your blood contains pyrokines then you might have an infection so you begin to run a fever as your body's way to kill the pathogen at the direction of the hypothalamus.
Hope these examples help!
Melting ice caps and glaciers
I believe it would be manual labor. During the Industrial Age of Employment, most people would have to do repetitive jobs, or manual labor. Design, engineer, and knowledge broker were not common during this time.
The Euglena was green because it had chloroplasts in it, just like plants. The body structure at the base of the tail that relates to this is the photo receptor. These two enabled it to photosynthesize food like plants, but it could also take food from its surroundings like animals.