This is my opinion- please note this is NOT a fact:
Scientists label planets and dwarf planets to further distinguish what actually classifies a planet. If scientists didn’t have a classification system, the argument could be made that solid matter in space could be named a “planet” (asteroids, moons, etc.). Having certain classification thresholds means that planets that could support life are identified.
Again- this is NOT fact, my simple opinion. I could be very wrong.
The innermost cells of the epidermis are continuously dividing through mitosis to form new cells. The newly formed cells move up through the epidermis toward the skin surface, while producing a tough, fibrous protein called keratin.
Hair cells Are found in both those systems
A control is the normal behavior you are testing the variable against. There are two types of variables. The independent variable is what you change to test what the dependent variable is, which is the variable that changes due to the independent variable, and what you generally record your data over.