The Cell

Every organisms are made up of cells. a cell is a self-contained unit in a whole organism and it is classified as a living thing. there are 50,000,000,000,000 in a human body. cells often come in different shapes and sizes but most cells are small-scale so a microscope is needed to observe. there are various types of cells and each cells prosecute own operations but making proteins and producing energy are common for most cells. some cells exist on own - for example, bacteria or single celled organism (amoeba) but most cells come together to form more complex multicellular organisms - for example, animals and plants. in a multicellular organism, each cells cooperate to complete an overall enterprise - for example, cells of heart to pump blood.