Biology

1. Sessile form of cnidarin.
5. Most diverse arthropods
6. density Measure of the number of individuals per unit area of habitat.
8. Helps determine the population size.
13. Aquatic, sessile animals that are either asymmetrical or radially symmetrical.
15. Factors that limit population regardless of size.
16. Gastrula's first indentation form in the mouth.
18. Study of relationship amongst organisms and the enviroment.
19. Unique stage in embryonic development of animals.
21. Spiny-skinned marine animals.
22. vascular system Enables echinoderms to move, sense their environment, acquire food, exchange gases, and get rid of metabolic wastes.

2. Population growth that stabilize indefinitely at the habitat' carrying capacity.
3. Factors that limit large population.
4. Immediate ancestor of animals.
7. Segmented animals with jointed appendages and a chitin-rich exoskeleton.
9. Improves flexibility and increases the potential for specialized body parts.
10. Unsegmented worms that molt periodically.
11. Population growth that is proportional to the size of the population.
12. Bodies consist of repeated segments.
14. Unsegmented animals that lack a coelom.
17. Free swimming form of cnidarin.
20. The three groups of primates are prosimians, monkeys, and ___.