Across
- 4. used for breathing by amphibians
- 8. producing your own body heat
- 9. trait of chordates, become gills or bones, muscles, and glands in animals with lungs
- 11. replaces the tissue in the fetal skeleton in all but agnatha and chondrichthyes
- 13. covering on mammals
- 14. flexible rod replaced by vertebrae in some animals
- 15. bony fish have this to regulate pressure internally
- 17. egg-laying mammals Echinda and Platypus
- 19. Use a placenta to feed young, born live
- 20. hook on top of the scale cuts down on friction in chondrichthyes
- 22. heart chambers in fish
Down
- 1. makes up Chondrichthyes skeleton
- 2. pouched mammals, koala, kangaroo, wombats, tasmanian devils
- 3. modified scales
- 5. animal gets heat from the environment sun, rocks, etc
- 6. shark tails, lobes 2 different sizes
- 7. heart chambers in amphibians
- 10. used on land for breathing by mammals, birds, and reptiles
- 12. used to breathe underwater, covered in bony fish exposed in cartilage fish
- 13. angelfish and bass tails, lobes same size
- 16. retains egg, young live off yolk and born live
- 18. heart chambers in crocs and gators, birds and mammals
- 21. lays eggs, amphibians, reptiles and birds a few mammals