1. What do the following two organisms have in common?Reef-building corals and hydrothermal-vent tube worms.

2. The green seaweed Leticia imaginarium contains the compound DMSP. When herbivores graze on the seaweed, however, an enzyme converts the DMSP to DMS and acrylic acid. To determine the effect that these chemicals have on herbivores, researchers fed two herbivore species—a sea urchin (white bar) and a snail (black bar)—pellets containing no chemicals (the control), DMSP, DMS, or acrylic acid and recorded the amount of pellets that the animals ate. Considering the results in the graph, which, if any, of these chemicals appears to act a deterrent to sea urchin herbivory?

3. Why don't marine microorganisms use fins to propel themselves through the water?

4. If the Gulf Stream did not exist, which of the following is least likely to happen as a result?

5. If you were investigating the chemical components of seawater located near deep-sea hydrothermal vents, what would you expect the origin of these dissolved solids to be?

6. Which echinoderms expel 'Cuverian tubules' and even their respiratory trees and viscera as a means of escaping predators?

7. Upwelling would provide the greatest benefit (with no attendant disadvantages) to which of these groups?

8. Some marine animals, like jellyfish, have alternate sexual and asexual generations.Given that the asexual generation produces plenty of young and takes less energy, what would be the benefit of also having a sexually-reproducing generation?

9. What kind of reef looks like a circle or oval surrounding a central lagoon?

10. Animals that build calcium-carbonate shells, including snails, bivalves, and corals, will be directly and negatively affected by which of these types of pollution?

11. For the part of the kelp listed, identify the part on a true plant that corresponds most closely: the blade.

12. For the part of the kelp listed, identify the part on a true plant that corresponds most closely: the holdfast.

13. Why might salt-marshes be called the 'livers of the sea?'

14. Why do oceanographers sometimes refer to a single 'world ocean?'

15. The fish you are studying produces larvae that drift with the current for some time before metamorphosing.You want to be able to chart the abundance and distribution of these larvae.Where would you look for them?

16. The ocean absorbs large quantities of carbon dioxide and marine animals (both those living now and those living millions of years ago) have used and incorporated this carbon in their exoskeletons.These processes have had what effect(s) on the earth's atmosphere?

17. You are raising some small stony (reef-building) corals in the lab, but they are producing coral skeleton very slowly.Which of the following changes to lab conditions would improve their rate of calcification?

18. A factory illegally releases dangerous chemicals into a river which leads out into a bay.Because of the behavior of currents in the area, the majority of chemicals remain within the bay.This situation will be worst for marine organisms in the bay that have offspring with which type of development?

19. Which of the following arthropods are ecologically important, because they are the basis for many marine food webs, including those involving baleen whales and commercially important fish?

20. When would you expect to see the greatest range of tidal heights (that is, the highest high tides and lowest low tides)?

21. Which of the following statements about seabirds is false?

22. Which of the following kinds of human interference/effects has the most direct negative influence on just-hatched sea turtles?

23. Which arthropods feed with their feet (also called 'cirri')?

24. In what area of the ocean would you expect to find phytoplankton (organisms that depend on light to survive) at lower depths?

25. From your reading, you know that different colors of light are absorbed at different depths in the ocean, and only certain wavelengths of light can penetrate the deep sea.What color should a deep-sea creature be, then, to remain unseen and camouflaged in its environment?