Answer:
organelle, organ, organism
Explanation:
As you can see in the picture below, an organelle is a small structure with specialized functions found inside a cell, it carries specific process needed for life. The organelles are of microscopic size, and togethery they form cells. They constitute the most basic unit of unicellular life.
Then organs are large parts found in organism, that are tissues performing similar functions, they are basic to carrying life process.
Think of the kidneys,liver,brain, lungs, etc.
Organisms are the whole, that what is the result of many organs functioning with many millions of groups of cells specialised to carry thousands of functions present for life to take place.
