The type of cellular organization found only in plants and animals is multicellularity.

Here's why:

* Multicellularity means an organism is made up of more than one cell.

* Plants and animals are both multicellular organisms, while many other life forms are single-celled (like bacteria and most protists).

While some features of cellular organization, like the presence of a nucleus, are found in both plants and animals, multicellularity is the defining characteristic that sets them apart from single-celled organisms.