What can be the results of dna mutation?

Some mutations don't have any noticeable effect on the phenotype of an organism.This can happen in many situations: perhaps the mutation occurs in a stretch of DNA with no function, or perhaps the mutation occurs in a protein-coding region,but ends up not affecting the amino acid sequence of the protein.

The answer to this will be from your lab notes/procedure. it would be best to ask another student who participated in the lab as we do not know what was done, what enzyme or if the temperature is celsius or fahrenheit. if i were to guess though i'd say the rate stopped due to enzyme denturing at high temperature

There would be no evaporation so no water cycle