Review the following dna sequences.
original dna sequence
a t t g c t a a g t c a
mutated dna sequence
a t t g a t a a g t c a
which type of mutation occurred?
insertion
deletion
there is no mutation.
substitution

The answer is substitution

Explanation:

Substitution is a kind of mutation that occurs when one nucleotide is change by a different one. In your example, only change the fifth nucleotide (C by A) so, this is an example of point mutation (onle one nucleotide changed).

The other options are differents kinds of mutations that the one shown in your question.

affects the water bodies: excessive use of fertilizers causes eutrophication. the fertilizers which are used on plants affect the quality of land on which it is used, further causing erosion of soil. the fertilizers used on plants contain harmful chemical fumes which affect the environment.

the endomembrane system i think