Across
- 2. a system of vessels in echinoderms
- 3. the predominant subphylum of the phylum Chordata
- 6. not equal or symmetric
- 7. an organ that connects the developing fetus to the uterine wall,
- 10. one of the two principal body types
- 11. type of asexual reproduction
- 13. an organism which derives the heat it requires from the environment
- 15. A growth that protrudes from a mucous membrane.
- 18. produces male and female gametes
- 19. eggs that are encased by extra-embryonic membranes
- 20. the internal skeleton of an animal
Down
- 1. the property of being divisible into symmetrical halves
- 4. relating to the bottom of the water
- 5. mammals that produces milk to feed young offspring
- 8. animal with no backbone
- 9. symmetry around a central axis
- 12. shedding of the exoskeleton of the previous life stage
- 14. rigid envelope that supports and protects the soft tissues
- 16. flexible tissue that lines joints and gives structure to body parts
- 17. an organism that maintains its body at a metabolically favorable temperature