Activated/turned on/used to make glycogen
Answer:Over time, carbon-14 decays in predictable ways. And with the help of radiocarbon dating, researchers can use that decay as a kind of clock that allows them to peer into the past and determine absolute dates for everything from wood to food, pollen, poop, and even dead animals and humans.
Explanation:
A. Group of cells
Cells - Tissue - Organ ...
If you want to know more - look for "Biological Organisation"
The two reasons are population increase and more activities require electronics. Hope that helps