a cell is a building unit of an organism. If yes,explain why
an organ is made up of tissues.a tissue is made up of group of cells lumped together performing same function.the most basic unit capable of sustaining life on its own is a cell. anything lower than a cell is incapable of sustaining life.therefore a cell is building block of an organism.
Cells, famously known as the building blocks of life are called so because they are the smallest existing entities out of which some are distinct and some are similar in funtion. They together forms the tissues (tissues are a group of similar cells specialised to perform the same function) which inturn further forms organs and then the organ system which indeed makes up the whole organism.