The animal kingdom is unique among eukaryotic organisms because most animal tissues are bound together in an extracellular matrix by a triple helix of protein known as collagen. Plant and fungal cells are bound together in tissues or aggregations by other molecules, such as pectin.
Explanation:
The ability to maintain different environments inside a single cell allows eukaryotic cells to carry out complex metabolic reactions that prokaryotes cannot. In fact, it's a big part of the reason why eukaryotic cells can grow to be many times larger than prokaryotic ones.
