* Eukaryotic cells: Animals are made up of cells that have a nucleus and other membrane-bound organelles.
* Multicellular: Animals are composed of multiple cells that work together to form tissues, organs, and organ systems.
* Heterotrophic: Animals cannot produce their own food and must consume other organisms (plants, animals, or organic matter) for energy.
* Mobile: Most animals are capable of movement at some stage in their life cycle, though some may be sessile (attached to a surface) as adults.
* Reproduce sexually: While some animals can reproduce asexually, the majority reproduce sexually, involving the fusion of gametes (sperm and egg).
* Have a defined body plan: Animals develop according to a specific pattern, resulting in a body shape and organization characteristic of their species.
* Respond to stimuli: Animals exhibit behaviors in response to environmental changes or internal signals.
Let me know if you'd like to dive deeper into any of these characteristics!