Cells because cells are the smallest units of life.
You might also be talking about Carbon since everything alive is made of carbon.
Or also Amino Acids since it helps build the cells and such.
They are called minerals
the building blocks of substances are called what atoms or molecules?
Because they combine in discrete definite proportions like building blocks.
Proteins are the building blocks of all organisms.
The branch of science that studies cells is called cell biology or cytology. It focuses on the structure, function, and behavior of cells, which are the basic building blocks of life.
A cells
the building blocks of the universe are called chemical elements or just elements
It is called construction.
organisms
These particles are the atoms.
Amino acids
Cells.