Astudent notices that her guppies reproduce most when her fish tank water is slightly alkaline. they stop reproducing if the water becomes acidic or if the water becomes too alkaline. this is an example of
question 18 options:

secondary succession

zones of tolerance

communities

intertidal zones

The correct answer is Zones of tolerance

Explanation:

All living organisms such as fish,plants and animals  need water to survive and also the require certain pH level of water in order to be healthy.Its a acid and base balance reaction.Strong acids dissolve into water and its changes water's pH.if water's pH level drops it becomes acidic suppose a fish waste ammonia releases and dissolves in water to form harmless ammonia ions,carbon dioxide ions and hydrogen ions even some limestone also rises pH level and water becomes more basic.To make the tank water alkaline, add some corals and aerate the tank water by fixing an air pump so that excess of carbon dioxide eliminate out and water pH level comes to neutral this is the reason water becomes slightly alkaline and the fishes are able to reproduce.

her next move would be to use agarose gel electrophoresis to separate the dna molecules of varying length and create a dna fingerprint.