Yes, all cells have a copy of the hereditary material, which is DNA (deoxyribonucleic acid). This is true for all living organisms, from single-celled bacteria to complex multicellular animals.

Here's why:

* DNA contains the genetic instructions: DNA holds the blueprint for building and maintaining an organism. It dictates everything from eye color to how the body functions.

* Cells need to function independently: Even in multicellular organisms, each cell must be able to carry out its own tasks. This requires the cell to have access to the genetic instructions encoded in DNA.

* Cell division: When a cell divides, it must pass on a complete copy of its DNA to each daughter cell. This ensures that all new cells inherit the same genetic information.

Exceptions:

* Red blood cells: In mammals, mature red blood cells lack a nucleus and therefore do not contain DNA. This is a specialized adaptation that allows them to carry more oxygen. However, they originated from cells that did have DNA.

* Certain viruses: Viruses are not considered living organisms and do not have cells. They contain either DNA or RNA as their genetic material, but they rely on host cells to replicate.

Therefore, the vast majority of cells in living organisms contain a copy of the hereditary material, DNA, which is essential for their function and survival.