The Correct answer is Robert Hooke. • Cells are the basic structural and functional unit of life. • The term “cells” was first coined in 1665 by British scientist Robert Hooke. He was the first person to study living things under a microscope and examined a thin slice of cork under a microscope and observed honeycomb-like structures. Robert Hooke called these structures cells. Soon after this Antonie Van Leuwenhoek made further discoveries by inventing his own microscope lenses that were more powerful than the microscopes of his time. He was the first person to observe human cells and bacteria under his microscope. • The stem cells were discovered by Martin Evans and Matt Kauffman. They identified, isolated and cultured the embryonic stem cells from a mouse blastocyst in 1981. Later, James Thomson and his subordinates isolated the embryonic stem cells from a human blastocyst. This helped the scientists to generate the building blocks of the human body in unlimited amounts. The discovery made it possible to have cell types for therapeutic purposes and new transplantation methods that were impossible in earlier times.