Plant cell the major classes of cells and tissues of roots, stems, leaves, flowers, and reproductive structures, each of which may be composed of several cell types. Parenchyma cells are living cells that have functions ranging from storage and support to photosynthesis (mesophyll cells) and phloem loading (transfer cells). Apart from the xylem and phloem in their vascular bundles, leaves are composed mainly of parenchyma cells. Some parenchyma cells, as in the epidermis, are specialized for light penetration and focusing or regulation of gas exchange, but others are among the least specialized cells in plant tissue, and may remain totipotent, capable of
External granular layer (cerebral cortex) regions, where it represents a strip of densely packed, small polymorphic cells deep to the molecular layer, distinguished from the actual pyramidal layer by the density and small size of these cells. ... External granular layer (cerebral cortex) The external granular layer of the cerebral cortex is commonly known as layer II. It is different from the internal granular layer of the cerebral cortex (commonly known as layer IV). Layer II is often lumped together with layer III and their union is referred to as layer II/III or layer 2/3. Layers I, II, and III are together referred to as