I find it too short and there is not enough evidence you have done enough to show what research you have already done (being fascinated by the powerful potential of 'two cells' is on the right track, but it's far too little).
Graduate school admissions committees are not interested in kids who think they are writing to their dads, like begging a boon from a king, they prefer to see in these letters their younger equals. No nonsense, details of publications, research and research interests.
The closest thing to flattery they do like is when it is clear you know their whole faculty, and exactly what kind of research they are currently doing. Tell them about X and his team, and why you will be on it, but also say why you hope to take courses taught by M, N, O, P, Q, Y, and Z, not merely listing names, but demonstrating you know what they are specialized in.
Are you talking about the Curie Institute on 45, rue d'Ulm, in Paris?