Concept:The discovery of cells is credited to the scientist who first observed and named them using a primitive microscope.Explanation:Robert Hooke examined a thin slice of dead cork under his microscope.He saw many small, box-like compartments that reminded him of monastery cells.He was the first to call these structures "cells" and published his findings in 1665.Robert Brown later discovered the nucleus inside a cell.Leeuwenhoek was the first to observe living cells (bacteria and protozoa) under a microscope.Rudolf Virchow proposed the theory that all cells arise from pre-existing cells.Answer:Robert Hooke