The figure shows the shape and structure of broad bean seeds. (1) Broad bean seeds are composed of _ _ _ _ _ and embryos, and embryos are composed of _ _ _ _ _ _ _ _. (2) Cotyledons can be coated with dilute iodine solution. (1) Vicia faba is a dicotyledonous plant. The seed consists of seed coat and embryo, and the embryo consists of embryo, hypocotyl, radicle and cotyledon.

(2) Cotyledons can be dyed blue by dilute iodine solution, which indicates that there is starch in cotyledons, and starch has the characteristic of turning blue when exposed to iodine.

(3) In the process of seed germination, radicle grows fastest, develops into root, embryo develops into stem and leaf, and hypocotyl develops into the part connecting stem and root.

Therefore, the answer is: (1) seed coat; Embryo, hypocotyl, radicle and cotyledon; (2) starch; (3) Stems and leaves