ecology/animal diversity

Several questions regarding ecology and animal diversity that I require answered for a (University level) Biology assignment. Please refer to the attached word document for the questions.

PART 1 – ANIMAL DIVERSITY

 Q1.      Hydra can move from one place to another by flexing the body and gripping the substrate with the tentacles and then looping the body over the mouth to gain a new position. Explain exactly what mechanisms and principles are involved in this movement? The full answer to this question involves the hydrostatic skeleton formed by the gastrovascular cavity and contractile cells.   [5-6 sentences]

 Q 2.   What reasons can you think of that might limit this type of body form to aquatic systems? [5-6 sentences]

Q 3.   What factors may limit the upper body size in forms like this? Part of this answer derives from your observation of the living Hydra in moving water.   [5-6 sentences]

Q 4.   Given the constraints of the rate at which oxygen can diffuse through tissue, what are the only two ways flatworms can become bigger? [3-4 sentences]

Q5.    By relating the form of movement of the nematode to its structure, describe and explain the body movement of nematodes. In answering this question, consider why the body has such a thick cuticle and why the blastocoelomic fluid is under pressure. What are the various functions of the blastocoelomic fluid?

[5-6 sentences]

Q 6.   What are the restrictions in the possible movements at each joint of an arthropod and how do they overcome these limits to allow for complex movement? [2 sentences]

Q 7.   What great evolutionary possibilities became available with the development of a true cellular middle layer or mesoderm?   [4 sentences]

PART 2 – RESTORATIVE ECOLOGY

 Q1. List and describe one method that ecologists are using to restore or rehabilitate degraded ecosystems in Australia, and the success of such a restoration program for the ecosystem. (Short essay question, 500 words, please list one or two references)