This sentence contains a comma splice. It has two independent clauses joined only by a comma. One way to revise the sentence is to separate it into two sentences by changing the comma to a period and then capitalizing the word it to start a new sentence.
One way to fix that sentence is to switch around the two phrases used; 'My mother and father are both scientists' and 'It must have been my destiny to become interested in biology.'
It must have been my destiny to spark an interest in Biology, as my mother and father are both scientists.
That's a way to fix that sentence used in your question.
Also, 'destiny' was spelled incorrectly.
This sentence may seem run on if you don't place a conjunction between the two phrases, or if the phrases are not switched.
If the sentence is to be used with a conjunction, it may end up like this....
My mother and father are both scientists, so it must have been my destiny to become interested in biology.
Or, you may just use a period, to change the two phrases used into two separate sentences.
Like this;
My mother and father are both scientists. For that reason, it must have been my destiny to become interested in biology.
ALSO, as you can see above, I have added a few words to the last sentence. Those three words, 'For that reason', give closure to the two sentences.
