Which of the statements about variation is not true? select one:
a. variation is differences in the size, shape, or color etc. of a particular species.
b. variation in a particular species allows for natural selection process to take place.
c. the amount of variation of a particular trait does not affect how quickly a trait evolves.
d. variation is necessary for a trait to evolve over time.

c. The amount of variation of a particular trait does not affect how quickly a trait evolves.

Explanation:

Variation is the diversity observed within a species. In a species all the organisms are not identical. They can vary in different characteristics like shape, size or colour. Variation can lead to natural selection because a particular variant of a trait can be favoured over the other ones and eventually  it becomes dominant in the population.

Evolution of a trait is also effected by the amount of variation present in that trait. More the variation, more different will be its response to the changing environment and more time can be required to incorporate these changes within an organism.

c. would be the answer : )

explanation:

an active site is a region that is present on an enzyme where the reactants or the substrate molecules we can say bind and experience a chemical reaction. the substrate is basically a reactant whose concentration is changing and that is converting into a product after binding at the active site of an enzyme