Explain the relationship between cells, tissues, organs, and organ systems in one complete paragraph

Many cells working together forms a tissue.  Many tissues working together forms organs. Many organs working together forms organ systems.  So it goes from general to most specific.  Organ systems are needed in order for life.  This proves that cells are the most basic units of life.

Organ system is made up of organs. Organs are made up of tissues. Tissues are made up of cells. Just like first comes world. Then, continent and so on...