Animal Crossword Puzzle

2. one whose body temperature fluctuates with the temperature of its surroundings.
3. an organism that possesses both male and female reproductive organs.
4. the free-swimming, umbrella-shaped body form of certain cnidarians.
5. a unique hydraulic system found in echinoderms.
7. an organism's body plan where it can be divided into two roughly mirror-image halves along a single plane.
8. lack of equality or equivalence between parts or aspects of something.
9. a specialized type of connective tissue that provides support and protection to joints and other parts of the body.
13. a gas-filled organ found in most bony fish.
15. a sedentary, cylindrical body form, characteristic of certain cnidarians like sea anemones and corals.
16. a temporary, disc-shaped organ that develops in the uterus during pregnancy.
18. organisms (like mammals and birds) that maintain a stable internal body temperature through internally generated heat.
20. a hard, internal skeletal system, typically made of bone or cartilage.

1. an animal lacking a backbone, such as an arthropod, mollusk, annelid, coelenterate, etc.
4. the process where an animal sheds its outer layer or covering.
6. an animal that has a backbone and a skeleton.
10. a terrestrially adapted egg, characterized by a shell and extra-embryonic membranes.
11. a hard, external skeleton that provides structural support and protection to certain animals.
12. specialized exocrine glands in mammals that produce milk to nourish their young.
14. plant and animal symmetry in which similar parts are arranged in a balanced way around the center of the body.
17. a form of asexual reproduction where a new organism develops as an outgrowth.
19. the bottom-dwelling organisms and the ecological region at the lowest level of a body of water.