Multicellular organisms do not grow by making duplicants in the sense of creating exact copies of themselves. Instead, they grow by cell division, a process where existing cells divide to create new cells.

Here's how it works:

* Mitosis: Multicellular organisms primarily grow through a process called mitosis. During mitosis, a single cell divides into two identical daughter cells. These daughter cells then have the potential to divide again, leading to an increase in the number of cells in the organism.

* Differentiation: As cells divide, they often undergo differentiation. This means they specialize into different types of cells with specific functions, such as muscle cells, nerve cells, or skin cells. This specialization allows multicellular organisms to develop complex tissues and organs.

Key differences between cell division and creating duplicants:

* Cell division is a gradual process: Growth happens over time as cells divide and differentiate.

* Cell division produces specialized cells: Unlike duplicants, which would be identical, cells divide and differentiate to form diverse cell types.

* Cell division is regulated: The growth and development of multicellular organisms are controlled by genes and signaling pathways that ensure proper development and prevent uncontrolled growth.

In summary, multicellular organisms grow through a complex process of cell division and differentiation, not by creating exact copies of themselves.