Chapter 9: Introduction to Animals

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