Search also in: Web News Encyclopedia Images. striking 1 adj Something that is striking is very noticeable or unusual. The most striking feature of those statistics is the high proportion of suicides..., He bears a striking resemblance to Lenin. â¦ strikingly adv usu ADV adj In one respect, however, the men really were strikingly similar., ...a strikingly handsome man... 2 adj Someone who is striking is very attractive, in a noticeable way. She was a striking woman with long blonde hair.
cell membrane. the outer boundary of the cytoplasm, a layer that controls what enters and leaves a cell.thin, flexible barrier around a cell, regulates what enters and leaves the cell. cell wall. a protective outer covering that lies just outside the cell membrane of plant cells.
Guard cell. Guard cells are specialized cells in the epidermis of leaves, stems and other organs that are used to control gas exchange. They are produced in pairs with a gap between them that forms a stomatal pore. The stomatal pores are largest when water is freely available and the guard cells turgid, and closed when water availability is critically low and the guard cells become flaccid. Photosynthesis depends on the diffusion of carbon dioxide from the air through the stomata into the mesophyll tissues.