A climber at altitude has potential energy due to efforts to lift him higher in gravity's grip. His elevation gives him the potential to create kinetic energy if he had the misfortune to fall off
Yes, while multicellular organisms remove waste through the urinary system, single celled organisms expel their metabolic waste with vacuoles
Food doesn't taste good during common cold because you can't smell it properly
Having a high surface area helps so yes in the human body villi is an example of a structure that increases surface area to increase absorption rates.
