Channel protein is a membrane protein that spans the phospholipidbilayer (a strongly non-polar environment).
Shelled protozoans became part of 7 layers
Urinary system. hope that helps
cephalocaudal principle
The cephalocaudal principle states that development proceeds from top to bottom. According to this principle, a child will gain physical control of their head first. After this, physical control will move downward to the arms and lastly to the legs.