Answer:I think that answer is b
Explanation:
Microevolution<span> happens on a small scale (within a single population), while </span>macroevolution<span> happens on a scale that transcends the boundaries of a single species. Despite their </span>differences<span>, evolution at both of these levels relies on the same, established mechanisms of evolutionary change: mutation.</span>
The answer is; catalyst
These proteins are called enzymes. They work by lowering the activation energy of reactants and hence speed up the biochemical reaction. They are not affected in the process hence one enzyme molecule can catalyze many reactions. An example of such an enzyme is carbonic anhydrase that enables carbon dioxide to dissolve in blood plasma as carbonic acid.
The skull is designed to protect the brain.