the answer is the first one: by producing random changes in an organism's genetic code
A bio-molecule is a chemical molecule that naturally occurs in living
organisms. Bio-molecules consist primarily of carbon and hydrogen, along
with nitrogen, oxygen, phosphorus and sulfur.
The four types of bio-molecules are carbohydrates, proteins, lipids and nucleic acids.
Enzymes are constructed from chains of amino acids and go through the usual four stages of protein assembly.
Enzymes are proteins.
Mud will keeo the foot print thing of it like this you cannot walk on water so there is no footprint sand blows easy so it wont stay either mud is soft and moldable so your footprint would stick and you cant have a footprint on rock cause its hard