please help me with my biology please 10points?

[matthook38]

13. During feeding, planarians extend a tubelike, muscular organ called the _____________ out of their mouths. (1 point)


14. A(n) ___________________ is the tube-shaped body form with a mouth surrounded by tentacles, which serves as the asexual stage in some cnidarians.
(1 point)


15. In _____________________, eggs remain inside the animal’s body and sperm are carried to the eggs. (1 point)


16. An animal whose blood moves throughout its body within blood vessels has a(n) _________. (1 point)


17. Echinoderms have ________, which are hollow, thin-walled structures that each have a suction cup on the end. (1 point)


18. List the characteristics common to all animals. Name at least three. (3 points)


19. How do structures of the digestive tracts of a flatworm and an earthworm differ? (3 points)


20. How is a sponge’s food-gathering technique adapted to its sessile lifestyle? (3 points)


21. A biologist places a single, living sponge in a saltwater tank. After several weeks, the biologist observes other small sponges living in the tank. Because the biologist is certain that no other sponge was introduced into the tank, what other explanation could you provide to explain the observation? (3 points)


22. Describe the body of a leech. In what way do the leech’s adaptations make it suited for its niche? (3 points)


23. Segmented tube worms that live near the vents grow to lengths of 1.5 m in contrast to the growth of related tube worms living in other environments, whose growth is measured only in centimeters at most. You hypothesize that the food that the worms eat is more abundant at the vents. When you collect samples of the worms, you discover that they have no mouth or other means of taking in food. Hypothesize how the tube worms are obtaining nutrients.
(3 points)


24. When natural disasters strike natural areas, often the only animals to survive are the insects. Explain why this might happen. (3 points)


25. What three methods do echinoderms use to get food? (3 points)

[chrisandlane]

there ya go!

[katiekatie]

do it yourself!
dont cheat now ;]
haha

[boredatskool]

22. Ummm a leech looks like a black blob of melted rubber. It is about 1-4 inches long, and moves more or less like an elastic band. It is adapted to latch on to its host (for it is a parasite) and draw blood without causing pain. For this purpose it has a numbing agent which it injects with a special needle-like tooth in it's mouth. Leeches are very good at getting into hard-to-reach places, making them extremely annoying. However, the leech can actually detect good healthy blood from sick blood. It prefers the sick blood, and therefore eliminates many natural diseases from fish and other marine organisms.