Mitochondria are membrane-bound cell organelles (mitochondrion, singular) that generate most of the chemical energy needed to power the cell's biochemical reactions. Chemical energy produced by the mitochondria is stored in a small molecule called adenosine triphosphate (ATP).
Its a Genetic thing, in which the albino child has received the Dominant albino trait and the sibling has not.
Lets consider the water drop as being part of the water in a lake. The water droplet evaporates and changes from a liquid state to a vapor state by gaining energy and travels up to the upper atmosphere. In the atmosphere the water droplet once again condenses in the clouds and is stored until it can be precipitated on to the land again in the form of rain or other forms of precipitation.
