Oh cool. Designer babies. I thought to myself.
It is not so formal. Probably you can change it like "Design babies, the amazing ideas suddenly fascinated me."
All of a sudden, I saw the future with a mixture of technological robots that resemble humans and designer design humans that behave like robots.
The opening is attractive. But maybe that would make the admission officers think that you are not so interested in biology?
Your last paragragh is a little bit confusing.
It is hard to drive such an ethical problem, so I suggest you clearing your head first.
What do you want to express? How can you state them logically and precisely?
And then to show your special intellectual vitality in an positive attitude.
Overall your essay has few grammatical problems and you can greatly improve it after you solve the problem of the last paragraph.
I will be appreciated if you can have a look on the second draft of my Cornell essay.
Wish you good luck!