What is the difference between mutation and adaptation?

Which of the following statements regarding anfinsen's denaturing experiments with ribonuclease a (rnase a) are valid? exposing the denatured protein to air oxidation and then dialysis to remove urea restored the protein to its original functionality. removing urea by dialysis and then allowing air oxidation of the denatured protein restored the protein to its original functionality. denaturing the protein with both urea and β-mercaptoethanol yielded an inactive protein. anfinsen concluded that protein folding is determined by its primary sequence.

What is called the "building block" of life?

What is thought to have caused the mass extinction at the end of the cretaceous period?