The human body is made of all of the above.
To answer this question, I’m going to start by talking about bigger things and moving us down into smaller things.
Let’s start with the human body. The body is a whole bunch of stuff covered in skin. So let’s focus on skin for a moment.
What is skin made of? The simple answer is skin cells (I’m ignoring the structures and levels of skin because it’s quite complex and we don’t need to consider it here). And other structures are like this – muscle is composed of muscle cells, bone of bone cells, nerves of nerve cells, etc.
So we know that the body is made of cells.
What are cells made of?
Cells are made of proteins, which are a type of molecule, and water, which is another molecule, and other things which are all made of molecules. Within the centre of the cell is DNA and RNA, both extremely complicated molecules.
So we know that the cells of the body are made up of molecules.
What are molecules made of?
Molecules are collections of atoms. Water is made up of oxygen and hydrogen atoms. Proteins are made of carbon, hydrogen, oxygen, and other elements.
So we know that the molecules that make up the cells of the body are made of atoms.
In the end, it is correct to say the body is made of cells. And it’s correct to say it’s made of molecules. And to say it’s made of atoms.