Starting at the smallest, most simple level and working your way up to the most complex, explain how the following terms are connected.

Note-these terms are not in order

Molecules, Atoms, Organism, Tissues, Cells, Organ Systems, Organs

Atoms are the smallest unit of the chemical elements.

Molecules are formed of atoms and are found in all the matter, non-living and living, and they make up the most fundamental structures of living beings.

The molecules further combine together to form a cell, which is the basic unit of life.

The tissue is formed of cells, which functions together to do a certain task. For example, connective tissue, muscle tissue, and neural tissue.

An organ refers to a system of tissues, which functions together on a bigger scale to perform certain kinds of functions within the body of an animal. The examples include the heart, brain, and lungs.

An organ system refers to a group of organs, which functions together to do specific functions of the body. For example, the respiratory system uses the respiratory muscles, airways, and lungs to inhale oxygen and discharge carbon dioxide in animals.

An organism is a self-contained, recognizable individual. It can be unicellular like amoeba or bacteria, or multicellular comprising of organs and organ systems. An example of a multicellular organism is a human being.

Before studying the structure and different functions of the human body it is necessary to understand the basic structure of an organism. We should have an idea about how simple structures assemble into complex structures. The following terms are connected in the following ways.

All the matter in the universe whether it be a solid, liquid or gas are composed of atoms. Atoms are the smallest unit of any substance and these are made up of subatomic particles such as electron, proton and neutron.

Two or more atoms combine to form a molecule such as water molecule, proteins, sugar molecule etc. These are considered as the chemical building blocks of all the structures of the body.

Cell is defined as the smallest autonomous functioning unit of a living organism. Even bacteria have a cellular structure. Cells together form tissue. Tissue is defined as a group of many related cells that work together to perform a particular function.

Tissues together combine to form an organ which perform more definite physiological functions. Many organs such as liver, heart, kidney etc combine to form organ systems.

Therefore the order is Atoms combine to form molecules, cells combine to form tissues, Tissues combine to form organs, Organs combine to form organ system.