How does the amount of substrate affect the reaction rate? as the amount of substrate increases the reaction rate a. goes up and down at random b. decreases c. increases d. stays the same with proof on y ur answer is correct .

As the amount of substrate increases the reaction rate increases until it reaches a maximum rate (Vmax) to which it remains constant.

The answer is microorganisms have rapid cell cycle.

Microorganisms are much simpler and much smaller organisms than humans. Because of their size and complexity, they reproduce in extremely rapid pace. For example, E. coli population is able to double each 20 minutes. This is, of course, not the case with humans.
For the mutation to become established, there must pass a few generations. So, if a useful mutation establishes in E. coli cell, in 20 minutes it will be present in the next generation, in 40 minutes it will be present in the generation after that, and so on. In the humans, years (not minutes) are necessary for the mutation to be passed down to the first generation. It needs less time to establish a mutation in E. coli than in humans.