Across
- 3. a hard, external covering that provides support and protection for many invertebrate animals
- 4. modified sweat glands that produce and secrete milk for nourishing infants.
- 5. an animal lacking a backbone
- 8. shed old feathers, hair, or skin, or an old shell, to make way for a new growth.
- 9. an animal of a large group distinguished by the possession of a backbone or spinal column
- 10. one of two principal body types occurring in members of the invertebrate animal phylum Cnidaria
- 13. a gas-filled organ in bony fish that helps them regulate buoyancy
- 14. an organism that possesses both male and female reproductive organs or tissues
- 15. plant and animal symmetry in which similar parts are arranged in a balanced way around the center of the body
- 16. a tough, flexible connective tissue that plays a crucial role in the musculoskeletal system
- 19. Eggs a type of egg that are laid by reptiles, birds, and some mammals
- 20. anything related to or occurring on the bottom of a body of water
- 21. an abnormal growth of tissue that projects from a mucous membrane
Down
- 1. the property of being divisible into symmetrical halves on either side of a unique plane.
- 2. the vascular organ in most mammals that unites the fetus to the uterus of the mother.
- 6. An organism whose body temperature is largely determined by heat exchange with its surroundings
- 7. dependent on or capable of the internal generation of heat.
- 11. an internal skeleton, such as the bony or cartilaginous skeleton of vertebrates.
- 12. a unique hydraulic system found in echinoderms
- 17. lack of equality or equivalence between parts or aspects of something
- 18. having or developing buds