Retina and fetus

[Juggler]

Hello! Could you please check if I got my homework right and, if not, help me with it? So here goes: http://imgur.com/OhPIy
The first is a scheme of a section of the retina of a human's eye. We're to name the elements of the retina marked as letters. That's what I have:
a - ganglion cell
b - bipolar cell
c - cone cell
d - rod cell
But I don't have even a slightest guess with e and f.. could you help me?

And regarding the other exercise: we're to complete the picture of a placenta by drawing the symbols of + (Rh+) and - (Rh-) and the symbols of the antigenes in such a manner that we'll depict an occurence of a hemolytic disease of the newborn. So I made it this way as I think during the first pregnancy (left picture) the child's blood won't have contact with the mother's until she gives birth. Then, as it would have a contact, she'll start producing antigenes and during her second pregnancy (right picture), there'll be antigenes on her side of the placenta. Is that right?

[aptitude]

There are three layers in the back of the eye: the retina, the choroid (which absorbs extra light), and the sclera. Thus, e is the choroid, and f is the sclera.

Yes, your answer for the second question is correct.

[Juggler]

Thank you