Biology

2. Unique stage in embryonic development of animals.
4. Sessile form of cnidarin.
7. density Measure of the number of individuals per unit area of habitat.
9. Helps determine the population size.
11. Free swimming form of cnidarin.
15. The three groups of primates are prosimians, monkeys, and ___.
16. Factors that limit large population.
19. Spiny-skinned marine animals.
21. Improves flexibility and increases the potential for specialized body parts.
22. Unsegmented animals that lack a coelom.

1. Segmented animals with jointed appendages and a chitin-rich exoskeleton.
3. Aquatic, sessile animals that are either asymmetrical or radially symmetrical.
5. Bodies consist of repeated segments.
6. Population growth that stabilize indefinitely at the habitat' carrying capacity.
8. Immediate ancestor of animals.
10. vascular system Enables echinoderms to move, sense their environment, acquire food, exchange gases, and get rid of metabolic wastes.
12. Population growth that is proportional to the size of the population.
13. Factors that limit population regardless of size.
14. Most diverse arthropods
17. Study of relationship amongst organisms and the enviroment.
18. Gastrula's first indentation form in the mouth.
20. Unsegmented worms that molt periodically.