Answer:
1. Cells.
2. Molecules.
3. Organs.
Step-by-step explanation:
1. Cells: are the most basic units of life. A cell can be defined as the fundamental or basic functional, structural and smallest unit of life for all living organisms. Some living organisms are unicellular while others are multicellular in nature.
A unicellular organism refers to a living organism that possess a single-cell while a multicellular organism has many (multiple) cells.
2. Molecules: are groups of two or more atoms bonded together. An example of a molecule is water, which is made up of hydrogen and oxygen atoms.
3. Organs: are specialized body tissues that come together. Some examples of organs found in humans are brain, bladder, kidney, liver, heart, intestine, eyes, lungs etc.