Which is the actual baby: the sperm, or the egg?

Question

Is it a sperm cell that eventually grows into a human baby, or is it the ovum that is, in essence, a baby that isn't yet born? 

Answer 1

A sperm carries either an X or Y chromosome, while an egg only carries an X chromosome. When the two pair, the chromosome carried by the SPERM determines whether it is a boy or a girl. XX - Girl XY - Boy