What is an enzyme? where can you find it?

Cattle with brown fur and cattle with white fur will produce a reddish roan calf . when examined closely, the calf show about an even number of brown hairs and white hairs that give a reddish appearance when viewed from far away. the fact that both the brown fur allele and the white fur allele are expressed equally in the offspring is an example of

Casts and mold are a type of preservation where the original material decays, leaving a mold in surrounding rock that can be filled with another sediment a. true b. false

This is a biological reaction due to a stimulus. i need this quickly !