jyoti bhatia
Last Activity: 8 Years ago
Living things have a level of complexity and organization not found in lifeless objects. At its most fundamental level, a living thing is composed of one or more cells. These units, too small to be seen with naked eye, are organized into tissues. A tissue is a series of cells that accomplish a shared function. tissues, in turn, form organs, like the kidney and stomach. a number of organs working together compose an organ system. An organism is a complex series of many organ systems.