Answer:
cell - tissue - organ - organ system -
organism
Step-by-step explanation:
The levels of organization in living organisms include the cells, tissues, organ-system and the whole organism.
- The cell is the first and smallest level. It forms the basic unit of all living organisms. An example is the red blood cell.
- A tissue is the second level, that represents a group of similar cells forming a layer in an organism which performs a particular function. An example of tissues in humans is the blood.
- Organ is the third level, that represents a group of similar tissues forming a layer which performs a specific function. An example of organs in humans is eyes.
- Organ-system is the fourth level of organization of life. It consists of similar organs which work together to perform specific functions. An example is the excretory system.
- Organism is the largest level, where all the organ systems work together to make up the organism. Thus, for an organism to perform well, all the cells, tissues, organs, and organ-systems must also function normally.