Cells - Introduction

Introduction

What do slimy earthworms, majestic lions, and giant redwood trees have in common with humans? We all have cells, tiny units of life that grow and duplicate, gather fuel and building materials, and make energy. CellsThe basic unit for living organisms; cells are structured to perform highly specialized functions. are present in all living things. Some living things, such as bacteria and some plants, consist of only one cell where all the functions of life take place. They are known as unicellularLiving things that have one cell. Protozoans are unicellular, for example.. The average human has 50 to 100 trillion cells. Living things with a great many cells that are joined together are called multicellularLiving things with many cells joined together..