Explain why, for each pregnancy, human
parents have a 50 percent probability of having
a boy and a 50 percent probability of having a
girl.

with each pregnancy there will all ways be a 50/50 chance, be cause there are only two types of genders that you can have. so there are only two probabilities

Explanation:

hey bro i looked it up on google the structure of the eye-spot in euglena viridie, e. ehrenbergii, and phacus pyriyorme is not as franzé haa described it. the so-called “crystal body” and “lens bodies” were not found in any of the individuals of the species examined by me. as earlier observers have stated, the eye-spot consists simply of a mass of pigment granules arranged in a single layer, and probably embedded in a protoplasmic framework, but the latter could not be seen, and its presence was only inferred from the fact that the pigment granules must be held together in some way, thd the eye-spot as a whole is capable of expansion, and that the pigment granules can be separated from each other.

hope this   and an i get brainlsiest

i know can you plzz me with this question im sorry i didt answer your question i just need hel.