(B) Seeds of a conifer - Pinus

Dissect a pine seed. The seed is enclosed by a hard, stony protective seed coat (the remnant of the integument). Break open the seed coat and cut the seed lengthwise. The white, oily material is the remnant of the megagametophyte (the reserve food). Embedded in the food material is the embryo. It consists of an axis with one end, the epicotyl (epi = upon), surrounded by about eight finger‑like cotyledons. Below the cotyledons is the hypocotyl (hypo = below) at the very end of which is the radicle, or root. The radicle is not visibly different from the hypocotyl.

What tissue in the seed serves as the food supply for the embryo's growth? What are two ways that the seed is a more efficient dispersal unit than a spore? Does the seed coat provide protection for the embryo in pines? How does the small embryo itself break through the seed coat? What is a cotyledon?