The cleanliness of a ecosystem or how healthy it is. It determines how clean an environment/ecosystem is. You need all types of animals living there, therefore making it more healthy. The more healthy, the more we can say that it is biodiverse.
The correct answer is...Once the enzyme binds to the specific substrate molecule, subtle structure changes occur in the active site, which are reverted when the reaction is over.
Hope this helps:)
Adaptation through natural selection