Mushrooms can grow in dark caves, while algae can grow in the waters of seas, lakes, and ponds. The cells are the tiny units of life in a plant. Tissues are the groups of cells that are very much alike in size and shape. Each of the cells in a tissue does similar work. The organs of several different tissues.
Tissues work together to do the job of an organ.
The systems are groups of organs working together to perform one big job, such as getting food for an organism. The organisms are whole living things. An organism is made up of several systems. The work of each system is necessary for the organism to live. An organism is a complete community of cells.