Sentence:  A completely new insight into living <WSD>cells</WSD> and their structure will be possible by use of a new technique which replaces visible light with ultraviolet radiation and combines a microscope with a color - TV system to view the results . 
Meaning of the word marked with <WSD> tags:  (biology) the basic structural and functional unit of all organisms; they may exist as independent units of life (as in monads) or may form colonies or tissues as in higher plants and animals