Read the incorrect sentence. write three to five sentences explaining what kind of run-on sentence it is and how to revise it.
my mother and father are both scientists, it must have been my destiny to become interested in biology.

This sentence is in fact a run on sentence.
To fix it you can:
1. Add a period: My mother and father are both scientists. It must have been my destiny to become interested in biology.
2. Add a semicolon: My mother and father are both scientists; it must have been my destiny to become interested in biology.
3. Add the word "so": My mother and father are both scientists so, it must have been my destiny to become interested in biology.

I hope this helps:)

The author's purpose is to be persuasive

Hey perhaps you should add the passage? then we'll be able to you! : )