A small amount of brain tissue from a person cannot be distinguished that monkey?

It is not true that a small amount of brain tissue from a person cannot be distinguished from monkey brain tissue.

Here's why:

* Genetics: Human and monkey DNA are different. Even a small sample of tissue contains DNA, which can be analyzed to determine the species.

* Cellular Structure: While some cells may be similar in appearance, the overall structure and organization of human and monkey brains differ at a microscopic level.

* Protein Markers: Specific proteins are expressed in different amounts in human and monkey brains. These proteins can be detected using techniques like immunohistochemistry.

While it might be challenging to distinguish small amounts of brain tissue with some techniques, it is not impossible. Advanced techniques in genetics, microscopy, and protein analysis can successfully differentiate human and monkey brain tissue.