bench definition, bench meaning | English dictionary. bench. n an apparatus for experimentation in optics, typically consisting of an adjustable arrangement of light source, lenses, prisms, etc. bench.
3 Principal characteristics of cells that make up epithelium. -Cells are closely apposed-they adhere to one another via specialized cell junctions-Exhibit both structural and functional polarity-Epithelium creates a selective barrier between the external environment and the underlying connective tissue.î î î.Cells are closely apposed-they adhere to one another via specialized cell junctions-Exhibit both structural and functional polarity-Epithelium creates a selective barrier between the external environment and the underlying connective tissue. î î î.
13. The main cells of xylem are tracheids and vessel elements (these are only in found in angiosperms). Tracheids and vessel elements are dead cells that have lost their cytoplasm. Only their cell wall impregnated with lignin (an impermeable biopolymer) remains.3. The main cells of xylem are tracheids and vessel elements (these are only in found in angiosperms). Tracheids and vessel elements are dead cells that have lost their cytoplasm. Only their cell wall impregnated with lignin (an impermeable biopolymer) remains.