Across
- 3. Bladder a gas-filled sac present in the body of many bony fishes, used to maintain and control buoyancy
- 9. an animal lacking a backbone, such as an arthropod
- 10. Symmetry the property of being divisible into symmetrical halves on either side of a unique plane
- 11. lack of equality or equivalence between parts or aspects of something
- 15. a free-swimming sexual form of a coelenterate such as a jellyfish
- 20. dependent on or capable of the internal generation of heat
- 21. an internal skeleton, such as the bony or cartilaginous skeleton of vertebrates
Down
- 1. firm, whitish, flexible connective tissue found in various forms in the larynx and respiratory tract, in structures such as the external ear, and in the articulating surfaces of joints
- 2. Eggs An air-breathing egg characterized by a shell and extraembryonic membranes
- 4. an animal of a large group distinguished by the possession of a backbone or spinal column
- 5. Vascular System a network of water vessels in the body, the tube feet being operated by hydraulic pressure within the vessels
- 6. a plant having stamens and pistils in the same flower
- 7. an organism that regulates its internal temperature by exchanging heat with its surrounding environment
- 8. shed old feathers, hair, skin, or an old shell, to make way for a new growth
- 12. Glands the milk-producing gland of women or other female mammals
- 13. a flattened circular organ in the uterus of pregnant mammals, nourishing and maintaining the fetus through the umbilical cord
- 14. having or developing buds
- 16. a rigid external covering for the body in some invertebrate animals
- 17. of, relating to or occurring at the bottom of a body of water
- 18. Symmetry symmetry around a central axis
- 19. a solitary or colonial sedentary form of a coelenterate such as a sea anemone