Hypoxia and Medicine

Biology Question. Help!?

1. If an ecosystem lost a keystone species, which outcome would you expect? A. A new keystone species would replace the old keystone species. B.The oxygen supply in the ecosystem would be depleted. C.The population numbers of other species would change dramatically. D.The temperature of the ecosystem would increase. 2. The Gulf of Mexico provides 72 percent of the shrimp harvested in U.S. waters. Those populations are at risk because of the dead zone in the Gulf of Mexico. Which statement best describes this dead zone? A.It is a zone of ocean water that has almost no oxygen. B.It is a zone of ocean water that has almost no carbon dioxide. C.It is a zone that formed when it lost its keystone species. D.It is a zone that's been depleted by sea urchins.

Public Comments

1. D and D do your own home work
2. C and A
3. Columbian's answer looks accurate. He posted it first, so I recommend you give him the best answer. A keystone species is basically the foundation of an ecosystem, so it would probably be the primary producer. Since the primary producer of a marine system is the diatom (a type of phytoplankton), and since the loss of the foundation will upset the rest of the life in the ecosystem, the answer should be C- such an event would have a remarkable impact on the population of other species. As for number 2, the answer is A: http://en.wikipedia.org/wiki/Dead_zone_%28ecology%29 The definition of a dead zone is apparently any hypoxic environment (hypoxic refers to an area with a low oxygen content). Therefore, the answer must be A, since this is basically the definition of a dead zone.