Zea mays

2.14
2.14 Diagram of the fine-structure of a relatively undifferentiated plant cell. The
protoplaSt is bounded by a thin primary wall (1) with a median middle lamella
(1). The plasmalemma (3) encloses the protoplaSt and this membrane also lines
the plasmodesmatal pores. Narrow membranous dcsmotubuks (4) traverse these
pores and link the endoplasmic reticulum (5) of adjacent protoplasts. Although
only partially indicated, the outer surfaces of the endoplasmic reticulum and alIter
nuclear membrane arc normally covered by tibosomes; the numerous free
cytoplasmic ribosomes arc not shown in this diagr