What is endosperm?
a. the leaves that are a part of the embryo
b. tissue that develops into a protective seed
c. coat surrounding the embryo
d. the female portion of a flowering plant via cotyledons
e. a source of food for the embryo
f. the male portion of a flowering plant

What is the significance of the protein-lined pits? a. protein attracts other proteins needed for atp synthesis within the cell. b. protein-lined pits are able to transport one molecule at a time down the concentration gradient within the cell. c. the polarity of proteins allows other polar molecules to attach and be transported in the cell by transport channels. d. receptors within the pits allow ligands to fuse and be transported into the cell by endocytosis.