sci choice board
Across
- 2. does not have a backbone
- 5. changes in form as animal becomes an adult
- 7. symmetry: can be split into left and right sides in only one way
- 9. protective membrane that surrounds the embryo
- 11. an organism that lives in or on another organism, harming it
- 12. symmetry: body parts are arranged in a circle around a center point
- 13. connects fetus to mother for nutrient and gas exchange
- 15. animal that heats its body from its environment
Down
- 1. animal that generates its body heat from the inside
- 3. skeleton is on the outside of the body
- 4. shedding and replacing of an exoskeleton, skin, or feathers
- 6. organs that exchange carbon dioxide for oxygen in water
- 8. skeleton is on the inside of the body
- 10. has a backbone
- 14. cannot be cut into equal halves