What is blood cell

Cell is the structural and functional unit of living things. Cells are the building blocks of our bodies. All living things are made of these tiny living units called cell. A cell is so small in size that you cannot look at it simply with your eyes. You need microscope to observe a cell. Cells were discovered after the invention of microscope.  The cell was first discovered and named by Robert hooke in 1665. He observed a thin slice of a cork under a microscope and noticed small boxes surrounded by walls. Which he named as cells. Microscope is one of the basic tools of a scientist. It is an instrument used to see small things. The apparent size of an object magnifies when seen under microscope. Do you know? • Your body has about 75 trillion cells. • Some of your nerve cells can live throughout your life. • Some white blood cells and intestine live only for three days. • Ostrich egg is the largest cell in the world. • It would take about 200 of your cells to fit on a full stop.