All terms in this list:

tissue: A group of similar cells that are organized to do a specific job.

organ: A structure that is made up of different tissues working together to perform a particular function.

organ system: A group of organs that together perform a function.

hibernation: A sleeplike state in which certain animals spend the winter.

stomata: Openings in a plant’s dermal tissue that control the exchange of water vapor, oxygen, and carbon dioxide with the atmosphere.

vascular system: Long tubelike tissues in plants through which water and nutrients move from one part of the plant to another.

root system: The system in a plant that anchors the plant and generally provides for the exchange of materials with soil.

shoot system: The system in a plant that includes structures for photosynthesis, support, storage, and the exchange of materials with the atmosphere; includes stems and leaves.

exoskeleton: The strong, flexible outer covering of some invertebrate animals, such as arthropods.

endoskeleton: An internal support system typically made of bone, cartilage, ligament, and tendon tissues. It is a distinguishing characteristic of vertebrate animals.