Both cilia and flagella spring directly from the cell-protoplasm, piercing the cell-membrane, when this is present.
We may also obtain cells with cytoplasm filling the whole of the cellular cavity or separated from the cell-membrane.
By the segmentation of the fertilized egg, now invested by cell-membrane, the embryo-plant arises.
The researches of Salkowski (p. 113) leave little doubt, however, that the cell-membrane is of the cellulosic type.
Meanwhile great advances had been made also in the knowledge of the mature framework of cell-membrane in plants.
cell membrane n.
The semipermeable membrane that encloses the cytoplasm of a cell. Also called cytomembrane, plasmalemma, plasma membrane.
|cell membrane |
The thin membrane that forms the outer surface of the protoplasm of a cell and regulates the passage of materials in and out of the cell. It is made up of proteins and lipids and often contains molecular receptors. The membranes of organelles within the cell are made of the same basic material as the cell membrane. In plant cells, the cell membrane is surrounded by a rigid cell wall. Also called plasma membrane. Compare cell wall. See more at cell.