What defines a mixture? a. it cannot be broken down into simpler substances. b. it can be described by a single chemical formula. c. it can be created through a chemical reaction. d. it can be broken down into its basic substances through physical means.

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