animals

2. eggs that are encased by extra-embryonic membranes,
3. one who cannot regulate its own body temperature
5. a cold-blooded animal with no backbone
8. lack of equality between parts or aspects of something
9. a rigid external covering for the body in some invertebrate animals
10. one of two principal body types occurring in members of the invertebrate animal phylum Cnidaria
12. anything associated with or occurring on the bottom of a body of water
15. organ that develops in the uterus during pregnancy
16. symmetry around a central axis, as in a starfish or a tulip flower.
18. animals of a large group distinguished by the possession of a backbone or spinal column
19. a network of water vessels in the body

1. dependent on or capable of the internal generation of heat
4. flexible connective tissue found in various forms in the larynx and respiratory tract,
6. an internal skeleton
7. a highly evolved and specialized organ present in pairs, one on each side of the anterior chest wall.
11. internal gas-filled organ that contributes to the ability of many bony fish to control their buoyancy
13. the property of being divisible into symmetrical halves on either side of a unique plane.
14. an extra piece of tissue that grows inside your body.
17. shed old feathers, hair, or skin, or an old shell, to make way for a new growth.