i belive that would be the work of D.N.A
A scab is a person who goes to work when the Union have called a strike.
The skin is not any thicker.. A person who works out has bigger muscles verses a person who does not work out
Because people inherit genes from their parents and the skin color itself from a thing called Melanin i believe and the higher level's on Melanin the darker the skin
A person who works on clocks is called a horologist.
a zebra ur welcom
A person who agrees to work but does not earn any money is called a volunteer.
auditor
Such a person could be called: Work Shy. Or sluggard
That would be an albino. A person suffering from Albinism Please se the related link below
A person or animal that has a lack of pigmentation or melanin in their skin or hair or eyes is called an albino. And the condition is commonly called Albinism and also called achromia, achromasia, or achromatosis.
An assistant.