[Solved] The half-life of nicotine is a few days. Light Microscope: An instrument that uses visible light and a system of lenses to magnify small objects, enabling the observation of cells and other small structures. Micrographs: Photographic or digital images taken through a microscope to magnify objects that are too small to be seen by the naked eye. Cell Theory: Theory that all organisms consist of one or more cells, which are the basic unit of life; all cells arise by division of preexisting cells; and all cells pass hereditary material to offspring. Multicellular Organism: An organism composed of multiple cells that are specialized to perform distinct functions, contributing to the overall functionality and survival of the organism.